Catheter and introducer needle assembly with needle shield

ABSTRACT

A catheter and introducer needle assembly with a needle shield is provided. The needle shield includes a means for preventing unwanted distal movement of the needle once the needle has been withdrawn into the needle shield. The needle shield also includes a means for connecting the needle shield to the catheter hub until the sharp distal tip of the introducer needle has been withdrawn into the needle shield. Thus, when the distal end of the introducer needle extends from the distal portion of the needle shield, the needle shield is connected to the catheter hub and when the sharp distal end of the introducer needle is withdrawn into the needle shield, the needle shield is disconnected from the catheter hub.

This application is a continuation-in-part of application Ser. No.09/590,600 filed Jun. 9, 2000, now abandoned, which is acontinuation-in-part of application Ser. No. 09/312,335 filed May 14,1999, now U.S. Pat. No. 6,379,333, which is a continuation-in-part ofapplication Ser. No. 09/057,718 filed Apr. 9, 1998, now U.S. Pat. No.6,004,294. This application is also a continuation-in-part ofapplication Ser. No. 09/499,331 filed Feb. 4, 2000, now abandoned, whichis a continuation-in-part of application Ser. No. 09/312,335 filed May14, 1999, now U.S. Pat. No. 6,379,333, which is a continuation-in-partof application Ser. No. 09/057,718 filed Apr. 9, 1998, now U.S. Pat. No.6,004,294. This application is also a continuation-in-part ofapplication Ser. No. 09/406,026 filed Sep. 24, 1999, now abandoned.

BACKGROUND OF THE INVENTION

The subject invention relates to a catheter and introducer needleassembly that includes a needle shield that will safely shield the sharpdistal tip of the introducer needle after the needle has been used toinsert the catheter into a patient. In addition, this invention includesa mechanism to connect the needle shield to the catheter until the sharpdistal tip of the introducer needle is covered by the needle shield.

Catheters, particularly intravascular (IV) catheters, are used forinfusing fluid, such as normal saline solution, various medicaments andtotal parenteral nutrition, into a patient, withdrawing blood from apatient or monitoring various parameters of the patient's vascularsystem. Peripheral IV catheters tend to be relatively short, andtypically are on the order of about two inches or less in length. Themost common type of IV catheter is an over-the-needle peripheral IVcatheter. As its name implies, an over-the-needle catheter is mountedover an introducer needle having a sharp distal tip. At least the distalportion of the catheter tightly engages the outer surface of the needleto prevent peelback of the catheter and thus facilitates insertion ofthe catheter into the blood vessel. The catheter and the introducerneedle are assembled so that the distal tip of the introducer needleextends beyond the distal tip of the catheter with the bevel of theneedle facing up away from the patient's skin.

The catheter and introducer needle assembly is inserted at a shallowangle through the patient's skin into a blood vessel. There are manytechniques for inserting such a catheter and introducer needle assemblyinto a patient. In one insertion technique, the introducer needle andcatheter are inserted completely into the blood vessel together. Inanother technique, the introducer needle is partially withdrawn into thecatheter after the initial insertion into the blood vessel. The catheteris then threaded over the needle and inserted completely into the bloodvessel.

In order to verify proper placement of the catheter in the blood vessel,the clinician confirms that there is flashback of blood in a flashbackchamber. The flashback chamber is typically formed as part of the needlehub. Once proper placement of the catheter into the blood vessel isconfirmed, the clinician applies pressure to the blood vessel bypressing down on the patient's skin over the blood vessel distal of theintroducer needle and the catheter. This finger pressure occludes or atleast minimizes further blood flow through the introducer needle and thecatheter. The clinician then withdraws the introducer needle, leavingthe catheter in place, and attaches an appropriate device to thecatheter. Such a device can include a fluid delivery device, a PRN, adeadender cap or a blood pressure monitoring probe. Once the introducerneedle is withdrawn from the catheter, the introducer needle is a “bloodcontaminated sharp” and must be properly handled.

In recent years, there has been great concern over the contamination ofclinicians with a patient's blood and a recognition that “bloodcontaminated sharps” must be disposed to avoid an accidental needlestick. This concern has arisen because of the advent of currentlyincurable and fatal diseases, such as Acquired ImmunosuppressiveDeficiency Syndrome (“AIDS”), which can be transmitted by the exchangeof body fluids from an infected person to another person. Thus, contactwith the body fluid of an AIDS infected person must be avoided. As notedabove, if an introducer needle has been used to place a catheter in ablood vessel of an AIDS infected person, the introducer needle, via itssharp distal tip, is a vehicle for the transmission of the disease.Although clinicians are aware of the need to properly handle “bloodcontaminated sharps”, unfortunately in certain medical environments,such as emergency situations or as a result of inattention or neglect,needlesticks with a contaminated introducer needle still occur.

As a result of the problem of accidental needlesticks by “bloodcontaminated sharps”, various needle shields have been developed.Generally, such needle shields work for their intended purpose but couldbe improved. For example, some needle shields are bulky, difficult touse, require special features or techniques to be operative, or mayleave the sharp distal tip exposed after use until the clinicianmanually activates the needle shielding mechanism.

In addition, some of these needle shields can be easily disconnectedfrom the catheter hub before the needle shield covers the sharp distaltip of the introducer needle. A mechanism to avoid this prematuredisconnection is a plurality of fingers longitudinally extending fromthe needle shield with tabs extending radially inwardly from the fingersthat engage the flange at the proximal end of the catheter hub. Thefingers and tabs hold the needle shield to the catheter. Theconfiguration of the fingers and tabs is designed such that the forceneeded to overcome the engagement between the fingers and tabs and thecatheter hub is greater than the typical force needed to move theintroducer needle proximally into the needle shield. However, once theintroducer needle has been fully withdrawn into the needle shield, theclinician can exert a greater proximally directed force to remove theneedle shield from the catheter hub. Thus the needle shield remainsengaged with the catheter until the introducer needle has beencompletely removed from the catheter and is safely shielded in theneedle shield. Unfortunately, this configuration does not consistentlyensure that the needle shield remains connected to the catheter hubuntil the introducer needle is locked in the needle shield. This may beundesirable because the contaminated needle could then be exposedincreasing the chances for an accidental needlestick.

SUMMARY OF THE INVENTION

It is therefore an object of this invention to provide a needle shieldthat is compact.

It is another object of this invention to provide a needle shield thatis simple and easy to use.

It is still another object of this invention to provide a needle shieldthat requires no special features or techniques to be operative.

It is yet another object of this invention to provide a needle shieldthat automatically shields the sharp distal tip of the introducer needleupon withdrawal of the introducer needle from the catheter.

It is a further object of this invention to provide a catheter andintroducer needle assembly with a needle shield where the needle shieldremains connected to the catheter until the needle shield covers thesharp distal tip of the introducer needle.

The catheter and introducer needle assembly with needle shield of thisinvention includes a catheter, an introducer needle and a needle shield.

The catheter has a distal end and a proximal end connected to the distalend of a catheter hub. The catheter is coaxially disposed over theintroducer needle and the distal portion of the catheter tightly engagesthe outer surface of the introducer needle to prevent peelback of thecatheter and thus facilitate insertion of the catheter into thepatient's blood vessel. Prior to use, the catheter is located about theintroducer needle so that the sharp distal tip of the introducer needleis distal of the distal end of the catheter.

The introducer needle has a sharp distal tip and a proximal endconnected to the distal end of a needle hub. A flashback chamber may bedefined in the needle hub. Typically a vented plug is located in theopen proximal end of the flashback chamber to allow air to escape fromthe flashback chamber when blood enters the flashback chamber from theintroducer needle. The introducer needle may also define, along a distalportion thereof, a discontinuous portion, which can take a number ofdifferent forms. For example, a slot, or an enlarged diameter portionformed on the introducer needle may be used. If an enlarged diameterportion is used it may have a tapered proximal portion or a tapereddistal portion or both. The taper can be oriented at almost any angle tothe longitudinal axis of the introducer needle. In certain embodiments,the distal portion may be oriented generally perpendicular to thelongitudinal axis of the introducer needle. However, the mainrequirement is that the discontinuous portion has any configuration thatcooperates with a lock associated with the needle shield to preventunwanted distal movement of the introducer needle with respect to theneedle shield. In other words, the sharp distal tip will not bere-exposed from the distal end of the needle shield once the sharpdistal tip has been withdrawn into the needle shield after use. Thediscontinuous portion may also cooperate with a means for preventingunwanted proximal movement of the introducer needle with respect to theneedle shield once the sharp distal tip of the introducer needle hasbeen proximally withdrawn into the needle shield. This preventsre-exposure of the sharp distal tip of the introducer needle from theproximal end of the needle shield.

The needle shield is defined by a housing having an internal cavitythrough which the introducer needle extends. A lock associated with theneedle shield prevents unwanted distal movement of the introducer needleonce the introducer needle has been proximally withdrawn into the needleshield. Also associated with the needle shield is a means for preventingunwanted proximal movement of the introducer needle once the sharpdistal tip of the introducer needle has been proximally withdrawn intothe needle shield.

Various locks can be used to prevent unwanted distal movement of thesharp distal tip of the introducer needle out of the needle shield oncethe sharp distal tip has been proximally withdrawn into the introducerneedle shield. For example, a transverse barrier that rides along theneedle shaft as the introducer needle is withdrawn into the needleshield and that moves in front of the sharp distal tip once the needletip is proximal of the transverse barrier may be used. In such anembodiment, no discontinuous portion is needed on the introducer needle.Alternatively, a lock may be used in conjunction with a discontinuousportion formed on the introducer needle. In such an embodiment, the lockallows the discontinuous portion of the introducer needle to move pastthe lock in a proximal direction but prevents movement of thediscontinuous portion past the lock in a distal direction. Such a lockcan take many forms and can include a spring gate, a leaf spring withone or a plurality of locking legs, where the locking legs have avariety of configurations, a tube having one or more inwardly andproximally directed tabs, a speed nut with one or more radially inwardlyand proximally directed tabs extending from the main body or a retentionplate with one or more radially inwardly directed tabs formed around themain body.

The spring gate has a generally U shaped configuration with a pair ofspaced apart tines. The introducer needle is disposed between the tinesand is moveable longitudinally past the tines. A biasing mechanismforces the spring gate up into contact with the introducer needle. Withthis embodiment, the discontinuous portion on the needle is preferablyan enlarged diameter portion. A tapered portion immediately proximal ofthe enlarged diameter portion on the introducer needle may be used tofacilitate proximal movement of the enlarged diameter portion past thespring gate. The enlarged diameter portion could be formed with adistally facing shoulder to provide a further positive engagement withthe spring gate and minimize the possibility that a clinician couldforce the sharp distal tip of the introducer needle distally out of theneedle shield during normal use and under normal conditions.

When the introducer needle is withdrawn proximally into the needleshield, the introducer needle rides past the tines of the spring gate.As the enlarged diameter portion passes by the tines, the enlargeddiameter portion engages the tines. This forces the spring gate torotate toward the proximal end of the introducer needle. The spring gateis also forced downwardly against the bias of the biasing mechanism.This movement by the spring gate allows the enlarged diameter portion ofthe introducer needle to move proximally past the spring gate. Once theenlarged diameter portion is proximal of the spring gate the biasingmechanism forces the spring gate upwardly and the tines of the springgate rotate toward the distal end of the introducer needle. Thismovement of the spring gate ensures that the main portion of theintroducer needle is located in the space between the tines of thespring gate so the tines extend up past the introducer needle. In thisposition, the spring gate abuts a proximal facing surface of a shoulderor wall in the housing to prevent further distal rotation of the springgate. Thus, if a clinician tries to advance the introducer needledistally, the enlarged diameter portion would engage the tines of thespring gate. In addition, the spring gate would engage the wall orshoulder in the housing and prevent the introducer needle from beingmoved distally.

Another lock that may be used to prevent unwanted distal movement of theintroducer needle once the sharp distal tip of the introducer needle hasbeen proximally withdrawn into the introducer needle shield is a leafspring. With the leaf spring, any configuration for the discontinuousportion can be used. However, preferably the discontinuous portion is anenlarged diameter portion on the introducer needle with a distallyfacing shoulder when the leaf spring is used.

The leaf spring has a proximal wall, a support leg and at least onelocking leg. Preferably, the support leg and the locking leg areconfigured such that the locking leg extends generally back toward theproximal end of the support leg. In this configuration the support legand the locking leg have a generally V-shape, with the apex of the Vfacing distally. Although this configuration is preferred, any otherconfiguration that biases the locking leg toward the introducer needlecould be used. For example, the locking leg could be generallyperpendicular to the support leg or oriented at some other angle lessthan 90 degrees. Alternatively, the locking leg could be formed so ithas a generally U-shaped or V-shaped configuration with a pair of spacedapart tines. With such a configuration the locking legs prevent unwanteddistal movement of the introducer needle in a manner analogous to thespring gate discussed above. In addition, the portion of the locking legthat rides along the introducer needle shaft could be contoured toapproximate a portion of the circumference of the introducer needle tominimize drag as the introducer needle rides past the locking leg.

The configuration of the leaf spring ensures that the locking leg isbiased toward and abuts the main portion of the introducer needle.However this bias still allows the locking leg to ride over the enlargeddiameter portion as the introducer needle is moved proximally into theneedle shield. Once the distally facing shoulder of the enlargeddiameter portion is moved proximally of the locking leg, the locking legmoves back into contact with the main portion of the introducer needle.Thereafter, if the introducer needle is moved distally, the locking legwill engage the distally facing shoulder and prevent further distalmovement of the introducer needle.

The leaf spring and housing could be configured to maximize themechanical engagement force between the locking leg and the introducerneedle. For example, the cavity where the lock is located could have atapered cross-section and the leaf spring could be disposed therein soit could move distally into the tapered cross-section.

In this embodiment of the leaf spring, the introducer needle would beproximally withdrawn into the needle shield just like in the previousembodiments until the discontinuous portion is proximal of the lockingleg. Thereafter, if the introducer needle is moved distally, the lockingleg engages the discontinuous portion and causes the lock to movedistally into the tapered cross-section of the cavity. This causes theleaf spring to engage the introducer needle with increasing force untilthe tapered cross-section prevents further distal movement of the leafspring. At this point, the locking leg forcefully engages thediscontinuous portion preventing distal movement of the introducerneedle.

In order to minimize drag on the introducer needle, the locking legcould be initially spaced apart from the introducer needle. In analternate embodiment, the locking leg could be held out of engagementwith the introducer needle by a finger and tab arrangement on the leafspring and the housing. The leaf spring is movable proximally withrespect to the housing by the engagement of the discontinuous portion ofthe introducer needle with the proximal wall of the leaf spring so thefinger and tab can be moved out of engagement with one another. Thisallows the locking leg to move into engagement with the introducerneedle by the inward bias of the locking leg. Thereafter, unwanteddistal movement is prevented as discussed above.

In another embodiment of the leaf spring, the cavity has a distalportion and a proximal portion where the diameter of the distal portionis larger than the diameter of the proximal portion. The leaf spring isdisposed in the cavity for proximal movement from the distal portion tothe proximal portion. When the leaf spring is disposed in the distalportion, the locking leg does not engage the introducer needle. As theintroducer needle is withdrawn proximally into the needle shield, thediscontinuous portion of the introducer needle engages the proximal wallof the leaf spring. This engagement causes the leaf spring to moveproximally with the introducer needle into the proximal portion of thecavity until the proximal wall of the leaf spring abuts the proximalwall of the housing. At this point, any further proximal movement of theleaf spring and the introducer needle is prevented.

When the leaf spring is in the proximal portion, the walls defining thecavity force the locking legs inwardly into engagement with theintroducer needle. The leaf spring includes flexible, outwardlyextending fingers. The inner walls of the proximal portion in the cavitydefine slots having a proximally facing wall for receiving the fingers.When the leaf spring is in the proximal portion so the proximal wall ofthe leaf spring abuts the proximal wall of the housing, the fingers arelocated in the slots so they are proximal of the proximally facing wall.Thus distal movement of the leaf spring is prevented by the engagementof the fingers and the proximally facing wall. As a result when thediscontinuous portion of the introducer needle engages the locking leg,distal movement of the introducer needle is prevented.

Alternatively, the locking leg can be oriented so it is generallyperpendicular to the support leg and can be formed with a small diameteropening formed therein. This opening is too small to allow the enlargeddiameter portion on the introducer needle to pass therethrough but islarge enough to allow the main portion of the introducer needle to passthrough.

The leaf spring is held in a biased position by the shaft of theintroducer needle. Thus, the locking leg rides along the introducerneedle shaft as the introducer needle is retracted into the needleshield. Once the distal end of the introducer needle has been retractedinto the needle shield and is proximal of the locking leg, the leafspring returns to its unbiased position. As such, the locking leg canmove so the small diameter opening in the locking leg will be alignedwith the sharp distal tip of the introducer needle. Thus, If theintroducer needle is moved distally with respect to the leaf spring, thedistal end of the introducer needle travels through and past the smalldiameter opening formed in the locking leg. However, the introducerneedle is prevented from being moved distally outside of the needleshield when the enlarged diameter portion on the introducer needleengages the small diameter opening formed in the locking leg.

Preferably, the housing includes at least one additional medial walladjacent to the locking leg. This medial wall includes an openingtherein to allow the main portion of the introducer needle to extendthrough the medial wall. This provides additional support for theintroducer needle and ensures that the introducer needle is aligned withthe small diameter opening in the locking leg when the leaf springreturns to its unbiased position.

A variation of the foregoing leaf spring includes an opening in thelocking leg with a diameter slightly larger than the diameter of theenlarged diameter portion of the introducer needle. The leaf spring alsoincludes a proximal wall defining an opening therein slightly largerthan the diameter of the shaft of the introducer needle but smaller thanthe diameter of the enlarged diameter portion. The leaf spring is alsoslidably disposed in the housing of the needle shield but has an endportion of the locking leg that is substantially held in place withrespect to the housing. This allows the locking leg to rotate in thehousing.

Prior to use when the sharp distal tip of the introducer needle extendsbeyond the distal end of the needle shield, the locking leg isperpendicular to the longitudinal axis of the introducer needle. In thisposition, the introducer needle extends through the opening in theproximal wall and the opening in the locking leg. Since the diameter ofthe opening in the locking leg is slightly larger than the diameter ofthe enlarged diameter portion, it can be retracted through the openingin the locking leg so the enlarged diameter portion is proximal of thelocking leg.

Once the enlarged diameter portion of the introducer needle engages theopening in the proximal wall, the leaf spring moves proximally with theintroducer needle until the proximal wall of the leaf spring abuts theproximal wall of the housing. Because one end of the locking leg issubstantially held in place with respect to the housing, this proximalmovement of the leaf spring causes the proximal leg to rotate clockwiseas seen in the FIGS. This changes the orientation of the opening in thelocking leg so that a plane defining that opening is no longerperpendicular to the longitudinal axis of the introducer needle.Instead, the opening is angled so that the effective diameter of theopening, i.e. the perpendicular dimension of the opening, is less thanthe diameter of the enlarged diameter portion. In addition, in thisposition, a detent associated with the leaf spring prevents subsequentdistal movement of the leaf spring. Thus any subsequent distal movementof the introducer needle is prevented since the enlarged diameterportion can not be moved through the opening in the locking leg.

An alternative lock that prevents distal movement of the sharp distaltip of the introducer needle out of the distal end of the needle shieldonce the sharp distal tip has been proximally withdrawn into the needleshield is a tube formed in the housing. Again, although most forms ofthe discontinuous portion could be used with this embodiment, thediscontinuous portion is preferably an enlarged diameter portion with adistally facing shoulder. The tube is located inside the housing toallow the introducer needle to pass therethrough and includes at leastone movable lanced protrusion or tab that extends proximally andinwardly into the tube. Preferably the lanced protrusion, or tab isbiased inwardly. Because the lanced protrusion or tab is movable, theenlarged diameter portion of the introducer needle with the distallyfacing shoulder can move proximally past the lanced protrusion or tab.Once the introducer needle has been withdrawn proximally into the needleshield such that the lanced protrusion or tab is distal of the distallyfacing shoulder, unwanted distal movement of the introducer needle willbe prevented when the distally facing shoulder engages the lancedprotrusion or tab.

Although the enlarged diameter portion having a distally facing shoulderis the preferred embodiment for the discontinuous portion, a notchformed in the introducer needle could be used as the discontinuousportion. When the introducer needle is withdrawn proximally into theneedle shield, one-of the lanced protrusions or tabs extends into thenotch. Thereafter, distal movement of the introducer needle is preventedwhen the lanced protrusion or tab engages the proximal edge of thenotch.

Yet another lock that prevents distal movement of the sharp distal tipof the introducer needle out of the distal end of the needle shield oncethe sharp distal tip has been proximally withdrawn into the needleshield is a speed nut that is formed in or added to the housing. Thespeed nut is located in the housing and defines a through hole and atleast one proximally oriented and radially inwardly extending tabadjacent the through hole. The through hole should be slightly largerthan the diameter of the introducer needle to allow the main portion ofthe introducer needle to pass therethrough. Because the tab isproximally oriented, the discontinuous portion can move proximally pastthe tab.

Once the introducer needle has been withdrawn proximally into the needleshield such that the tab is distal of the discontinuous portion, anydistal movement of the introducer needle will be prevented when thediscontinuous portion engages the tab. If an enlarged diameter portionis used for the discontinuous portion, it would be desirable to includea distally facing shoulder on the enlarged diameter portion to ensurefirm engagement with the tab. Alternatively, the discontinuous portionmay be a notch formed in the needle. When the introducer needle isproximally withdrawn into the needle shield the tab drops into the notchto thereby prevent any further distal movement of the needle when thetab engages the proximal edge of the notch. To avoid difficulties inaligning the tab and the notch, the speed nut could be formed with aplurality of tabs, each of which is configured to engage the notch.Alternatively, the introducer needle could be formed with a plurality oflongitudinally displaced notches located around the circumference of theintroducer needle.

In still another embodiment of the lock that prevents distal movement ofthe sharp distal tip of the introducer needle out of the distal end ofthe needle shield once the sharp distal tip has been proximallywithdrawn into the needle shield, a retention plate is located on aproximal face of a medial wall formed in the housing. The wall definesan opening therein that has a diameter large enough to allow theintroducer needle and the discontinuous portion to pass through. Theretention plate defines at least one, but preferably a plurality ofradially inwardly directed tabs. A cut out portion that has a radiussubstantially equal to or slightly larger than the radius of the mainportion of the introducer needle but less than the radius of theenlarged diameter portion is defined between the tabs. In thisembodiment, the discontinuous portion is preferably an enlarged diameterportion with a distally facing shoulder. As the introducer needle iswithdrawn into the needle shield, the main portion of the introducerneedle rides past the retention plate with little or no interference. Asthe introducer needle moves proximally with respect to the needleshield, the enlarged diameter portion of the introducer needle engagesthe retention plate and the tabs flex proximally so the enlargeddiameter portion can travel proximally past the retention plate. Oncethe enlarged diameter portion of the needle is proximal of the retentionplate, the tabs return to their unflexed position and abut the proximalface of the medial wall. Any subsequent distal movement of theintroducer needle is prevented when the enlarged diameter portionengages the tabs of the retention plate since the housing wall preventsthe tabs from flexing distally out of the way of the enlarged diameterportion.

The means for preventing further proximal movement of the introducerneedle once the sharp distal tip of the introducer needle has beenproximally withdrawn into the needle shield may take a number of forms.For example, where the discontinuous portion is an enlarged diameterportion, the housing may include a proximal opening that has a diametersufficient to allow the main portion of the introducer needle to extendtherethrough but that is too small to allow the enlarged diameterportion of the introducer needle from passing therethrough.Alternatively, regardless of the configuration of the discontinuousportion of the introducer needle or where no discontinuous portion isused on the introducer needle, a tether connected to the needle hub andthe needle shield could be used.

The needle shield also preferably includes a spring clip that connectsthe needle shield to the catheter hub and that maintains this connectionuntil the sharp distal tip of the introducer needle has been withdrawninto the needle shield and locked in place. This spring clip can takemany forms.

In one embodiment, the needle shield includes a spring clip that has aclip arm that engages the catheter hub. The spring clip is biased to aposition where the clip arm does not engage the catheter hub. The springclip is held in a biased position where the clip arm engages thecatheter hub by the introducer needle shaft. Thus, as long as theintroducer needle extends distally past the spring clip, the clip armremains engaged with the catheter hub and the catheter hub staysconnected with the needle shield. Once the sharp distal tip of theintroducer needle is withdrawn proximally past the spring clip, the cliparm moves out of engagement with the catheter hub. This allows thecatheter hub to be separated from the needle shield. This configurationensures that the needle shield remains engaged with the catheter untilthe introducer needle has been completely removed from the catheter andis safely shielded in the needle shield.

The spring clip can be used in combination with any of the locksdiscussed above for preventing unwanted distal movement of theintroducer needle with respect to the needle shield. In addition, thespring clip can be formed integrally with or separately from any ofthose locks.

The specific configuration of the spring clip can take many differentforms and can be oriented in the housing in many different ways. Forexample, the spring clip can have a generally V or. U shapedconfiguration. In this embodiment, the spring clip is located in thehousing so it is perpendicular to the longitudinal axis of theintroducer needle such that the V or U configuration is readily apparentfrom an end cross-sectional view of the needle shield. Thus one leg ofthe V is held in its biased position, adjacent to the other leg, bydirect contact with the shaft of the introducer needle. In thisarrangement, the spring clip includes a clip arm that extends generallyparallel to the longitudinal axis of the introducer needle and engages adetent on the catheter hub that is oriented generally perpendicular tothe longitudinal axis of the clip arm. When the introducer needle iswithdrawn proximal of the spring clip, it returns to its unbiasedposition such that the clip arm moves transversely, i.e. generallyperpendicularly to the longitudinal axis of the introducer needle, outof engagement with the catheter hub.

In an alternate embodiment, the spring clip is generally straight and isflexed into its biased position by the shaft of the introducer needle.In this embodiment, the clip arm has a hook configuration with one legof the hook extending perpendicular to the longitudinal axis of theintroducer needle with the hook facing distally. When the introducerneedle is moved proximal of the spring clip, it returns to its unbiasedposition such that the clip arm moves transversely out of engagementwith the catheter hub.

The spring clip can also be generally V or U shaped but oriented in thehousing so it is aligned with the longitudinal axis of the introducerneedle such that in a top cross-sectional view of the needle shield, theV or U configuration is apparent. In this configuration, the clip armextends generally parallel to the longitudinal axis of the introducerneedle and directly engages the catheter hub. However, a separatebiasing arm extending generally perpendicular to the longitudinal axisof the introducer needle and connected to each of the legs of the V or Uis required so the introducer needle can bias the spring clip intoengagement with the catheter hub. Each biasing arm defines an openingtherein and through which the introducer needle extends to achieve thisbiasing requirement. Once the introducer needle is moved proximal of thebiasing arm, the legs of the spring clip can move to their unbiasedposition out of engagement with the catheter hub. Alternatively, thespring clip may be formed with only one leg such that the spring cliphas a generally L-shaped shaped configuration.

Where the leaf spring uses a locking leg that is generally perpendicularto the introducer needle, the spring clip can be associated with thelocking leg. The spring clip can be pivotally connected to the needleshield housing such that it is caused to pivoted between a clippedposition and an unclipped position by the movement of the locking leg.Alternatively, the spring clip can be formed as a hook extendingdistally from the locking leg such that movement of the locking leg fromthe unshielded to the shielded position causes the hook to move from aclipped position to an unclipped position.

With the foregoing embodiments using a biasing arm, a means forminimizing drag on the introducer needle may be used. Such a means is aflap or finger extending from the opening in the biasing arm generallyparallel to the longitudinal axis of the introducer needle.Alternatively, where two biasing arms are used, a pin and tethercombination can be used. The pin extending through the biasing armsholds the openings in proper alignment so the introducer needle does notcatch on the sides of the openings. A tether connected to the pin andthe needle hub pulls the pin out of the biasing arms and allows thespring clip to return to its unbiased position.

Where two biasing arms are used, interlocking fingers may be located onthe ends of the biasing arms such that, once the introducer needle iswithdrawn proximal of the biasing arms, the interlocking fingers locktogether to ensure that a non-defeatable transverse barrier is formed bythe biasing arms.

In still another embodiment of the spring clip, the spring clip can beformed with a generally X shaped configuration. In this embodiment, thespring clip is oriented in the housing so the X shape is aligned withthe longitudinal axis of the introducer needle such that in a topcross-sectional view of the needle shield, the X shape of the springclip is apparent. In this embodiment, the introducer needle holds thedistal portion of the legs of the X apart so they engage the inside ofthe catheter hub. Thus, once the introducer needle is withdrawn proximalof the intersection of the legs, the distal portion of the legs can moveinwardly out of engagement with the catheter hub.

With all of the foregoing embodiments, the clip arm can be configured soit engages either the inside or the outside of the catheter hub. Inaddition, the clip arm can be configured frictionally or mechanically toengage the catheter hub. If a mechanical engagement is desired, the cliparm can have a detent thereon that engages a complementary detent formedon the catheter hub. Complementary detents can include, for example, aslot and a finger, or a post of any geometric shape. Regardless of thespecific configuration used, the main requirement is to have the cliparm engage the catheter hub so it is difficult for the clinician toremove the catheter hub from the needle shield until the sharp distaltip of the introducer needle is shielded in the needle shield.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiments are illustrated in the drawings in which likereference numerals refer to like elements and in which:

FIG. 1 is a perspective view of a standard catheter and introducerneedle assembly with the needle shield of this invention with thecatheter in partial cross-section;

FIG. 2 is a perspective view of an integrated catheter and introducerneedle assembly with the needle shield of this invention;

FIG. 3A is an enlarged elevation view of the distal portion of theintroducer needle with one embodiment of the discontinuous portionthereon used in the catheter and introducer needle assembly with theneedle shield of this invention;

FIG. 3B is an enlarged elevation view of the distal portion of theintroducer needle with a second embodiment of the discontinuous portionthereon used in the catheter and introducer needle assembly with theneedle shield of this invention;

FIG. 3C is an enlarged elevation view of the distal portion of theintroducer needle with a third embodiment of the discontinuous portionthereon used in the catheter and introducer needle assembly with theneedle shield of this invention;

FIG. 3D is an enlarged elevation view of the distal portion theintroducer needle with a fourth embodiment of the discontinuous portionthereon used in the catheter and introducer needle assembly with theneedle shield of this invention;

FIG. 3E is an enlarged elevation view of the distal portion of theintroducer needle with a fifth embodiment of the discontinuous portionthereon used in the catheter and introducer needle assembly with theneedle shield of this invention;

FIG. 3F is an enlarged elevation view of the distal portion of theintroducer needle with a sixth embodiment of the discontinuous portionthereon used in the catheter and introducer needle assembly with theneedle shield of this invention;

FIG. 3G is an enlarged elevation view of the distal portion of theintroducer needle with a seventh embodiment of the discontinuous portionthereon used in the catheter and introducer needle assembly with theneedle shield of this invention;

FIG. 4 is a cross-sectional view of the needle shield with a firstembodiment of the lock that prevents unwanted distal movement of theintroducer needle and the distal portion of the introducer needle withthe sharp distal tip of the introducer needle extending from the distalend of the needle shield;

FIG. 5 is a cross-sectional view of the needle shield with the firstembodiment of the lock that prevents unwanted distal movement of theintroducer needle and the distal portion of the introducer needle withthe sharp distal tip of the introducer needle withdrawn into the needleshield;

FIG. 6 is a cross-sectional view of the needle shield with the firstembodiment of the lock that prevents unwanted distal movement of theintroducer needle and the distal portion of the introducer needle withthe sharp distal tip of the introducer needle locked in the needleshield;

FIG. 7 is a perspective view of the spring gate that is used in thefirst embodiment of the lock shown in FIGS. 4 through 6 that preventsunwanted distal movement of the introducer needle;

FIG. 8 is a perspective cross-sectional view of the needle shield with asecond embodiment of the lock that prevents unwanted distal movement ofthe introducer needle and the distal portion of the introducer needlewith the sharp distal tip of the introducer needle extending from thedistal end of the needle shield;

FIG. 9 is a cross-sectional view of the needle shield with the secondembodiment of the lock that prevents unwanted distal movement of theintroducer needle and the distal portion of the introducer needle withthe sharp distal tip of the introducer needle locked in the needleshield;

FIG. 10 is a perspective view of the leaf spring that is the secondembodiment of the lock shown in FIGS. 8 and 9 that prevents unwanteddistal movement of the introducer needle;

FIG. 11 is a perspective cross-sectional view of the needle shield witha third embodiment of the lock that prevents unwanted distal movement ofthe introducer needle and the distal portion of the introducer needlewith the sharp distal tip of the introducer needle extending from thedistal end of the needle shield;

FIG. 12 is a cross-sectional view of the needle shield with the thirdembodiment of the lock that prevents unwanted distal movement of theintroducer needle and the distal portion of the introducer needle withthe sharp distal tip of the introducer needle locked in the needleshield;

FIG. 13 is a perspective view of the leaf spring that is the thirdembodiment of the lock shown in FIGS. 11 and 12 that prevents unwanteddistal movement of the introducer needle;

FIG. 14 is a schematic cross-sectional view of the needle shield with afourth embodiment of the lock that prevents unwanted distal movement ofthe introducer needle and the distal portion of the introducer needlewith the sharp distal tip of the introducer needle extending from thedistal end of the needle shield;

FIG. 15 is a schematic cross-sectional view of the needle shield withthe fourth embodiment of the lock that prevents unwanted distal movementof the introducer needle and the distal portion of the introducer needlewith the sharp distal tip of the introducer needle locked in the needleshield;

FIG. 16 is a schematic cross-sectional view of the needle shield withthe fifth embodiment of the lock that prevents unwanted distal movementof the introducer needle and the distal portion of the introducer needlewith the sharp distal tip of the introducer needle extending from thedistal end of the needle shield;

FIG. 17 is a schematic cross-sectional view of the needle shield with asixth embodiment of the lock that prevents unwanted distal movement ofthe introducer needle and the distal portion of the introducer needlewith the sharp distal tip of the introducer needle extending from thedistal end of in the needle shield;

FIG. 18 is a schematic cross-sectional view of the needle shield withthe sixth embodiment of the lock that prevents unwanted distal movementof the introducer needle and the distal portion of the introducer needlewith the sharp distal tip of the introducer needle locked in the needleshield;

FIG. 19 is a perspective cross-sectional view of the needle shield witha seventh embodiment of the lock that prevents unwanted distal movementof the introducer needle and the distal portion of the introducer needlewith the sharp distal tip of the introducer needle extending from thedistal end of in the needle shield;

FIG. 20 is a perspective cross-sectional view of the needle shield withthe seventh embodiment of the lock that prevents unwanted distalmovement of the introducer needle and the distal portion of theintroducer needle with the sharp distal tip of the introducer needlelocked in the needle shield;

FIG. 21 is a perspective view of the leaf spring that is the seventhembodiment of the lock shown in FIGS. 19 and 20 that prevents unwanteddistal movement of the introducer needle;

FIG. 22 is a schematic cross-sectional view of the needle shield with aneighth embodiment of the lock that prevents unwanted distal movement ofthe introducer needle and the distal portion of the introducer needlewith the sharp distal tip of the introducer needle extending from thedistal end of in the needle shield;

FIG. 23 is a schematic cross-sectional view of the needle shield withthe eighth embodiment of the lock that prevents unwanted distal movementof the introducer needle and the distal portion of the introducer needlewith the sharp distal tip of the introducer needle locked in the needleshield;

FIG. 24 is a distal end view of the leaf spring that is the eighthembodiment of the lock that prevents unwanted distal movement of theintroducer needle having the orientation shown in FIG. 22;

FIG. 25 is a distal end view of the leaf spring that is the eighthembodiment of the lock that prevents unwanted distal movement of theintroducer needle having the orientation shown in FIG. 23;

FIG. 26 is a cross-sectional view of the needle shield with a ninthembodiment of the lock that prevents unwanted distal movement of theintroducer needle and the distal portion of the introducer needle withthe sharp distal tip of the introducer needle extending from the distalend of the needle shield;

FIG. 27 is a cross-sectional view of the needle shield with the ninthembodiment of the lock that prevents unwanted distal movement of theintroducer needle and the distal portion of the introducer needle withthe sharp distal tip of the introducer needle locked in the needleshield;

FIG. 28 is a perspective cross-sectional view of the tube that is theninth embodiment of the lock shown in FIGS. 26 and 27 to preventunwanted distal movement of the introducer needle;

FIG. 29 is a cross-sectional view of the needle shield with a tenthembodiment of the lock that prevents unwanted distal movement of theintroducer needle and the distal portion of the introducer needle withthe sharp distal tip of the introducer needle extending from the distalend of in the needle shield;

FIG. 30 is a cross-sectional view of the needle shield with the tenthembodiment of the lock that prevents unwanted distal movement of theintroducer needle and the distal portion of the introducer needle withthe sharp distal tip of the introducer needle locked in the needleshield;

FIG. 31 is a cross-sectional view of the needle shield with the tenthembodiment of the lock that prevents unwanted distal movement of theintroducer needle and the distal portion of the introducer needle shownin FIG.3F with the sharp distal tip of the introducer needle locked inthe needle shield;

FIG. 32 is a perspective view of the speed nut that is the tenthembodiment of the lock shown in FIGS. 29 through 31 to prevent unwanteddistal movement of the introducer needle;

FIG. 33 is an exploded perspective view of a catheter, introducer needleand the needle shield with an eleventh embodiment of the lock thatprevents unwanted distal movement of the introducer needle and a firstembodiment of the spring clip that connects the needle shield to thecatheter hub until the sharp distal tip of the introducer needle islocked in the needle shield;

FIG. 34 is a partial cross-sectional view of the needle shield with theeleventh embodiment of the lock that prevents unwanted distal movementof the introducer needle, the first embodiment of the spring clip thatconnects the needle shield to the catheter hub until the sharp distaltip of the introducer needle is locked in the needle shield, a portionof the introducer needle and the proximal portion of the catheter hubwith the sharp distal tip of the introducer needle extending from thedistal end of in the needle shield and the needle shield connected tothe catheter hub;

FIG. 35 is a partial cross-sectional view of the needle shield with theeleventh embodiment of the lock that prevents unwanted distal movementof the introducer needle, the first embodiment of the spring clip thatconnects the needle shield to the catheter hub until the sharp distaltip of the introducer needle is locked in the needle shield, the distalportion of the introducer needle and the proximal portion of thecatheter hub with the sharp distal tip of the introducer needle lockedin the needle shield and the needle shield disconnected from thecatheter hub;

FIG. 36A is a perspective view of the first embodiment of the springclip shown in FIGS. 33 through 35 that connects the needle shield to thecatheter hub until the sharp distal tip of the introducer needle islocked in the needle shield;

FIG. 36B is a perspective view of a variation of the first embodiment ofthe spring clip shown in FIG. 36A that connects the needle shield to thecatheter hub until the sharp distal tip of the introducer needle islocked in the needle shield;

FIG. 36C is a perspective view of still another variation of the firstembodiment of the spring clip shown in FIG. 36 that connects the needleshield to the catheter hub until the sharp distal tip of the introducerneedle is locked in the needle shield;

FIG. 37A is a perspective view of the retention plate that is theeleventh embodiment of the lock shown in FIGS. 33 through 35 thatprevents unwanted distal movement of the introducer needle;

FIG. 37B is a schematic view, in partial cross-section, of a variationof the retention plate shown in FIG. 37A abutting the proximal face ofthe medial wall of the housing for the needle shield;

FIG. 37C is a schematic view, in partial cross-section, of still anothervariation of the retention plate shown in FIG. 37A abutting the proximalface of the medial wall of the housing for the needle shield;

FIG. 38 is a cross-sectional view of the needle shield shown in FIG. 34taken along line 38—38 showing how the clip arm of the spring clip wouldmove along a ramp formed in the housing;

FIG. 39 is a cross-sectional view of the needle shield shown in FIG. 35taken along line 39—39 showing how the clip arm of the spring clip wouldmove along a ramp formed in the housing;

FIG. 40 is a schematic perspective view of a first embodiment of thespring clip with a transverse barrier that connects the needle shield tothe catheter hub until the sharp distal tip of the introducer needle islocked in the needle shield and a portion of the introducer needle and aportion of the catheter hub where the sharp distal tip of the introducerneedle would be extending from the distal end of the needle shield andthe needle shield would be connected to the catheter hub;

FIG. 41 is a schematic perspective view of the spring clip shown in FIG.40 where the sharp distal tip of the introducer needle would be lockedin the needle shield and the needle shield would be disconnected fromthe catheter hub;

FIG. 42 is an exploded perspective view of a catheter, introducerneedle, tether and the needle shield with a second embodiment of aspring clip with a transverse barrier that connects the needle shield tothe catheter hub until the sharp distal tip of the introducer needle islocked in the needle shield;

FIG. 43 is a cross-sectional view of the needle shield with the secondembodiment of the spring clip with a transverse barrier that connectsthe needle shield to the catheter hub until the sharp distal tip of theintroducer needle is locked in the needle shield, a portion of theintroducer needle, the tether, the needle shield, and the proximalportion of the catheter hub with the sharp distal tip of the introducerneedle extending from the distal end of the needle shield and the needleshield connected to the catheter hub;

FIG. 44 is a cross-sectional view of the needle shield with the secondembodiment of the spring clip with a transverse barrier that connectsthe needle shield to the catheter hub until the sharp distal tip of theintroducer needle is locked in the needle shield, the distal portion ofthe needle hub, the distal portion of the introducer needle, the tether,and the proximal portion of the catheter hub with the sharp distal tipof the introducer needle locked in the needle shield and the needleshield disconnected from the catheter hub;

FIG. 45 is a perspective view of the second embodiment of the springclip with a transverse barrier shown in FIGS. 42 through 44;

FIG. 46 is an exploded perspective view of an integrated catheter, anintroducer needle and the needle shield with a first embodiment of anintegrated clip lock that connects the needle shield to the catheter hubuntil the sharp distal tip of the introducer needle is locked in theneedle shield and that prevents unwanted distal movement of theintroducer needle;

FIG. 47 is a perspective partial cross-sectional view of the needleshield with the first embodiment of the integrated clip lock thatconnects the needle shield to the catheter hub until the sharp distaltip of the introducer needle is locked in the needle shield and thatprevents unwanted distal movement of the introducer needle, a portion ofthe introducer needle and the proximal portion of the catheter hub withthe sharp distal tip of the introducer needle extending from the distalend of the needle shield and the needle shield connected to the catheterhub;

FIG. 48 is a perspective partial cross-sectional view of the needleshield with the first embodiment of the integrated clip lock thatconnects the needle shield to the catheter hub until the sharp distaltip of the introducer needle is locked in the needle shield and thatprevents unwanted distal movement of the introducer needle, the distalportion of the introducer needle and the proximal portion of thecatheter hub with the sharp distal tip of the introducer needle lockedin the needle shield and the needle shield disconnected from thecatheter hub;

FIG. 49 is a perspective view of the first embodiment of the integratedclip lock that is shown in FIGS. 46 through 48 that connects the needleshield to the catheter hub until the sharp distal tip of the introducerneedle is locked in the needle shield and that prevents unwanted distalmovement of the introducer needle;

FIG. 50 is a perspective view of a third embodiment of a spring clipwith a transverse barrier that connects the needle shield to thecatheter hub until the sharp distal tip of the introducer needle islocked in the needle shield;

FIG. 51 is a perspective partial cross-sectional view of a fourthembodiment of a spring clip with a transverse barrier that connects theneedle shield to the catheter hub until the sharp distal tip of theintroducer needle is locked in the needle shield, a portion of theintroducer needle, a portion of the tether and the proximal portion ofthe catheter hub with the sharp distal tip of the introducer needleextending from the distal end of in the needle shield and the needleshield connected to the catheter hub and a first embodiment of aninterlock that prevents defeat of the transverse barrier;

FIG. 52 is a perspective partial cross-sectional view of the needleshield with the fourth embodiment of the spring clip with a transversebarrier that connects the needle shield to the catheter hub until thesharp distal tip of the introducer needle is locked in the needleshield, the distal portion of the introducer needle, the distal portionof the tether and the proximal portion of the catheter hub with thesharp distal tip of the introducer needle locked in the needle shieldand the needle shield disconnected from the catheter hub and a firstembodiment of an interlock that prevents defeat of the transversebarrier;

FIG. 53 is a perspective view of the fourth embodiment of the springclip with a transverse barrier that is used in the needle shield shownin FIGS. 51 and 52 to connect the needle shield to the catheter hubuntil the sharp distal tip of the introducer needle is locked in theneedle shield and a first embodiment of an interlock that preventsdefeat of the transverse barrier;

FIG. 54 is a perspective partial cross-sectional view of the needleshield with a first embodiment of the integrated clip lock that connectsthe needle shield to the catheter hub until the sharp distal tip of theintroducer needle is locked in the needle shield and that preventsunwanted distal movement of the introducer needle, a portion of theintroducer needle and the proximal portion of the catheter hub with thesharp distal tip of the introducer needle extending from the distal endof the needle shield and the needle shield connected to the catheter huband a first embodiment of a tethered trigger to disconnect the springclip from the catheter hub;

FIG. 55 is a perspective partial cross-sectional view of the needleshield with the second embodiment of the integrated clip lock thatconnects the needle shield to the catheter hub until the sharp distaltip of the introducer needle is locked in the needle shield and thatprevents unwanted distal movement of the introducer needle, a portion ofthe introducer needle and the proximal portion of the catheter hub withthe sharp distal tip of the introducer needle extending from the distalend of the needle shield and the needle shield connected to the catheterhub;

FIG. 56 is a perspective partial cross-sectional view of the needleshield with the second embodiment of the integrated clip lock thatconnects the needle shield to the catheter hub until the sharp distaltip of the introducer needle is locked in the needle shield and thatprevents unwanted distal movement of the introducer needle, the distalportion of the introducer needle and the proximal portion of thecatheter hub with the sharp distal tip of the introducer needle lockedin the needle shield and the needle shield disconnected from thecatheter hub;

FIG. 57 is a perspective view of the second embodiment of the integratedclip lock shown in FIGS. 55 and 56 to connect the needle shield to thecatheter hub until the sharp distal tip of the introducer needle islocked in the needle shield and to prevent unwanted distal movement ofthe introducer needle;

FIG. 58 is a perspective partial cross-sectional view of the needleshield with a fifth embodiment of a spring clip with a transversebarrier that connects the needle shield to the catheter hub until thesharp distal tip of the introducer needle is locked in the needleshield, a portion of the introducer needle, a portion of the tether andthe proximal portion of the catheter hub with the sharp distal tip ofthe introducer needle extending from the distal end of the needle shieldand the needle shield connected to the catheter hub;

FIG. 59 is a perspective partial cross-sectional view of the needleshield with a sixth embodiment of the spring clip with a transversebarrier that connects the needle shield to the catheter hub until thesharp distal tip of the introducer needle is locked in the needleshield, a portion of the introducer needle, a portion of the tether andthe proximal portion of the catheter hub with the sharp distal tip ofthe introducer needle extending from the distal end of in the needleshield with the needle shield connected to the catheter hub;

FIG. 60 is a perspective partial cross-sectional view of the needleshield with the sixth embodiment of the spring clip with a transversebarrier that connects the needle shield to the catheter hub until thesharp distal tip of the introducer needle is locked in the needleshield, the distal portion of the introducer needle, the distal portionof the tether and the proximal portion of the catheter hub with thesharp distal tip of the introducer needle locked in the needle shieldand the needle shield disconnected from the catheter hub;

FIG. 61 is a perspective view of the sixth embodiment of the spring clipwith a transverse barrier shown in FIGS. 59 and 60 that connects theneedle shield to the catheter hub until the sharp distal tip of theintroducer needle is locked in the needle shield;

FIG. 62 is a schematic view of a portion of the clip arm showing analternative embodiment for the engagement mechanism between the needleshield and the catheter hub;

FIG. 63 is a schematic view of a portion of the clip arm showing anotheralternative embodiment for the engagement mechanism between the needleshield and the catheter hub;

FIG. 64 is a perspective view of a portion of the biasing arm showing analternative embodiment for the engagement mechanism between the needleand the biasing arm;

FIG. 65 is a perspective view of a portion of the biasing arm showinganother alternative embodiment for the engagement mechanism between theneedle and the biasing arm;

FIG. 66 is an exploded perspective view of an integrated catheter,introducer needle and needle shield with the eleventh embodiment of thelock that prevents unwanted distal movement of the introducer needle andthe second embodiment of the spring clip that connects the needle shieldto the catheter hub until the sharp distal tip of the introducer needleis shielded in the needle shield;

FIG. 67 is a perspective partial cross-sectional view of the needleshield with the eleventh embodiment of the lock that prevents unwanteddistal movement of the introducer needle and the second embodiment ofthe spring clip that connects the needle shield to the catheter hubuntil the sharp distal tip of the introducer needle is shielded in theneedle shield, a portion of the introducer needle and the proximalportion of the catheter hub with the sharp distal tip of the introducerneedle extending from the distal end of the needle shield and the needleshield connected to the catheter hub;

FIG. 68 is a perspective partial cross-sectional view of the needleshield with the eleventh embodiment of the lock that prevents unwanteddistal movement of the introducer needle and the second embodiment ofthe spring clip that connects the needle shield to the catheter hubuntil the sharp distal tip of the introducer needle is shielded in theneedle shield, the distal portion of the introducer needle and theproximal portion of the catheter hub with the sharp distal tip of theintroducer needle locked in the needle shield and the needle shielddisconnected from the catheter hub;

FIG. 69 is a perspective view of the second embodiment of the springclip shown in FIGS. 66 through 68 that connects the needle shield to thecatheter hub until the sharp distal tip of the introducer needle isshielded in the needle shield;

FIG. 70 is an exploded perspective view of an integrated catheter,introducer needle and the needle shield with a seventh embodiment of thespring clip with a transverse barrier that connects the needle shield tothe catheter hub until the sharp distal tip of the introducer needle isshielded by the needle shield and a tether;

FIG. 71 is a perspective partial cross-sectional view of the needleshield with the seventh embodiment of the spring clip with a transversebarrier that connects the needle shield to the catheter hub until thesharp distal tip of the introducer needle is shielded by the needleshield, a portion of the introducer needle, the tether and the proximalportion of the catheter hub with the sharp distal tip of the introducerneedle extending from the distal end of the needle shield and the needleshield connected to the catheter hub;

FIG. 72 is a perspective partial cross-sectional view of the needleshield with the seventh embodiment of the spring clip with a transversebarrier that connects the needle shield to the catheter hub until thesharp distal tip of the introducer needle is shielded by the needleshield, the distal portion of the introducer needle, the distal portionof the tether and the proximal portion of the catheter hub with thesharp distal tip of the introducer needle locked in the needle shieldand the needle shield disconnected from the catheter hub;

FIG. 73 is a perspective view of the seventh embodiment of the springclip with a transverse barrier shown in FIGS. 70 through 72, thatconnects the needle shield to the catheter hub;

FIG. 74 is a partial cross-sectional view of the needle shield with aneighth embodiment of the spring clip with a transverse barrier thatconnects the needle shield to the catheter hub until the sharp distaltip of the introducer needle is shielded by the needle shield and thedistal portion of the introducer needle and the proximal portion of thecatheter hub with the sharp distal tip of the introducer needleextending from the distal end of the needle shield with the needleshield connected to the catheter hub;

FIG. 75 is a partial cross-sectional view of the needle shield with theeighth embodiment spring clip with a transverse barrier that connectsthe needle shield to the catheter hub until the sharp distal tip of theintroducer needle is shielded by the needle shield, and the distalportion of the introducer needle and the proximal portion of thecatheter hub with the sharp distal tip of the introducer needle lockedin the needle shield with the needle shield disconnected from thecatheter hub;

FIG. 76 is a perspective partial cross-sectional view of the needleshield with a modified version of the seventh embodiment of the lockthat prevents unwanted distal movement of the introducer needle and thedistal portion of the introducer needle with the sharp distal tip of theintroducer needle extending from the distal end of in the- needle shieldwherein the needle shield has a clip that connects the needle shield tothe catheter hub until the sharp distal tip of the introducer needle isshielded by the needle shield; and

FIG. 77 is a perspective partial cross-sectional view of the needleshield with the modified version of the seventh embodiment of the lockthat prevents unwanted distal movement of the introducer needle and thedistal portion of the introducer needle with the sharp distal tip of theintroducer needle locked in the needle shield wherein the needle shieldhas a clip that connects the needle shield to the catheter hub until thesharp distal tip of the introducer needle is shielded by the needleshield.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the term “proximal” refers to a location on the catheterand introducer needle assembly with the needle shield of this inventionthat, during normal use, is closest to the clinician using the deviceand farthest from the patient in connection with whom the device isused. Conversely, the term “distal” refers to a location on the catheterand introducer needle assembly of this invention that, during normaluse, is farthest from the clinician using the device and closest to thepatient in connection with whom the device is used.

As used herein, the term “top”, “up” or “upwardly” refers to a locationon the catheter and introducer needle assembly with the needle shield ofthis invention that, during normal use, is radially away from thelongitudinal axis of the device and away from the patient's skin.Conversely, as used herein, the term “bottom”, “down” or “downwardly”refers to a location on the catheter and introducer needle assembly withthe needle shield of this invention that, during normal use, is radiallyaway from the longitudinal axis of the device and toward the patient'sskin.

As used herein, the term “in” or “inwardly” refers to a location withrespect to the catheter and introducer needle assembly with the needleshield of this invention that, during normal use, is toward the insideof the device. Conversely, as used herein, the term “out” or “outwardly”refers to a location with respect to the catheter and introducer needleassembly with the needle shield of this invention that, during normaluse, is toward the outside of the device.

This invention is described herein using like reference numbers for likeelements in the different embodiments. Although this invention isdescribed herein in connection with a typical peripheral IV catheter aswell as a peripheral IV catheter with an integrated extension tube (an“integrated catheter”), it is to be understood that this invention isapplicable to other catheters, For example, this invention is applicableto extended dwell catheters requiring the needle to be connected to theneedle hub by a stylet as well as other medical devices where it isdesirable for a needle to be shielded after use. In addition, while thisinvention is satisfied by embodiments in many different forms, there areshown in the drawings and herein-described in detail, preferredembodiments of the invention with the scope of the invention measured bythe appended claims.

The catheter and introducer needle assembly of this invention isidentified generally by the numeral 10 and defines a longitudinal axisextending therethrough. It includes a catheter assembly 20 and anintroducer needle assembly 30 that includes a needle shield 40. See FIG.1. Catheter assembly 20 may include an integrated extension tube 25. SeeFIG. 2. Such an integrated catheter is described generally in U.S. Pat.No. 5,697,914. As noted above, it is to be understood that the needleshield 40 of this invention can be used in connection with such anintegrated catheter.

Catheter assembly 20 includes a catheter 21 that has a proximal end, adistal end and a catheter hub 24 affixed to catheter proximal end.Suitable materials for catheter 21 include, but are not limited to,thermoplastic resins such as fluorinated ethylene propylene (FEP),polytetrafluoroethylene (PTFE), polyurethane and the like. Preferably,catheter 21 is formed from a thermoplastic hydrophilic polyurethane thatsoftens with exposure to physiological conditions present in thepatient's body. Suitable materials for catheter hub 24 include, but arenot limited to, thermoplastic polymeric resins such as polycarbonate,polystyrene, polypropylene and the like. Catheter hub 24 may include aradially outwardly extending tab, which is useful for advancing catheter21 into the patient's blood vessel.

Introducer needle assembly 30 includes introducer needle 31 having asharp distal tip 32 defined by a bevel and a proximal end connected to aneedle hub 34. Introducer needle 31 is preferably formed from stainlesssteel and has a longitudinal axis that is generally parallel to thelongitudinal axis of catheter and introducer needle assembly 10. Needlehub 34 can include an integrated flashback chamber having an openproximal end. Needle hub 34 may be formed from the same types ofmaterials that are used to form catheter hub 24. Of course, othermaterials could be used to form needle hub 34. Preferably, the openproximal end is closed to fluid flow by a vented plug 36 which allowsair but not fluid to flow therethrough.

Introducer needle assembly 30 also includes needle shield 40, whichincludes housing 41 defining an internal cavity 42 therein. Housing 41also defines a proximal opening 43 and a distal opening 45 incommunication with internal cavity 42. This allows introducer needle 31to extend longitudinally through housing 41. The diameters of cavity 42,proximal opening 43 and distal opening 45 are at least slightly largerthan the diameter of the main portion of introducer needle 31. Thisallows introducer needle 31 easily to pass through needle shield 40.Preferably, cavity 42 and distal opening 45 are at least slightly largerthan any discontinuous portion formed on introducer needle 31 asdescribed hereinafter. This: allows the distal portion of introducerneedle 31 to be withdrawn into housing 41 but prevents introducer needle31 from being withdrawn proximally from needle shield 40 as describedhereinafter.

Where the spring clip, as described hereinafter, of this invention isnot used, housing 41 may include a radially extending flange 46 and aplurality of longitudinally extending fingers 47. Fingers 47 may includeradially inwardly directed projections 48. Fingers 47 and projections 48engage catheter hub 24 to hold introducer needle assembly 30 togetherwith catheter assembly 20. Typically, catheter hub 24 includes aradially projecting thread or ear 44 at its proximal end to facilitatethe connection of another device thereto. This provides a portion ofcatheter hub 24 for fingers 47 and projections 48 to engage so thatcatheter hub 24 and introducer needle assembly 30 remain connected untilintroducer needle 31 is removed from catheter assembly 20 and isshielded by needle shield 40.

Introducer needle 31 includes a discontinuous portion formed thereonalong a distal portion thereof. The discontinuous portion may take manyforms. For example, it can be an enlarged diameter portion 38, see FIGS.3A, 3B, 3C and 3G, or a notch 39, see FIGS. 3D and 3G, or a combinationof an enlarged diameter portion 38 and a notch 39, see FIGS. 3E, 3F and3G. Where the discontinuous portion 38 is an enlarged diameter portion,the proximal portion 38 a may be tapered and the distal portion 38 b maybe a distally facing shoulder oriented generally perpendicular to thelongitudinal axis of introducer needle 31. See e.g. FIG. 3A.Alternatively, distal portion 38 b could be tapered. See e.g. FIG. 3C.This taper can be at just about any angle between almost parallel to andperpendicular to the longitudinal axis of introducer needle. Preferably,enlarged diameter portion 38, such as shown in FIGS. 3A, 3C, 3F and 3G,is formed on introducer needle 31 by centerless grinding a largerdiameter introducer needle. Although enlarged diameter portion 38 isshown in the FIGS. as being circumferentially disposed about the shaftof introducer needle 31, it is to be understood, that enlarged diameterportion 38 could be formed asymmetrically about the shaft of introducerneedle 31. For example, enlarged diameter portion could be formed as acrimped portion on introducer needle 31. See FIGS. 3B and 3E. For theavoidance of doubt, as used herein the term diameter refers to thelength of a straight line passing through the center of an object.

Where the discontinuous portion that is used for introducer needle 31 isenlarged diameter portion 38, it should have a diameter greater than thediameter of proximal opening 43 regardless of the specific configurationused for enlarged diameter portion 38. This provides one mechanism toensure that introducer needle 31 cannot be pulled in a proximaldirection completely out of needle shield 40. This is because enlargeddiameter portion 38 blocks further proximal movement of introducerneedle 31 through proximal opening 43. Alternatively, a washer 49 havingan opening therein with a diameter slightly larger than the diameter ofthe main portion of introducer needle 31 but smaller than the diameterof enlarged diameter portion 38 can be placed into cavity 42 abuttingthe proximal wall of cavity 42. In this position, the opening of washer49 is aligned with proximal opening 43. Thus washer 49 would preventenlarged diameter portion 38 from passing through proximal opening 43.

Alternatively, if notch 39 were used as the discontinuous portion or ifno discontinuous portion were used on introducer needle, a tether 50could be used to connect needle shield 40 with needle hub 34. See forexample FIG. 42. Tether 50 must be configured such that its effectivelength will not allow sharp distal tip 32 to be pulled proximallycompletely out of needle shield 40.

The diameter of enlarged diameter portion 38 preferably should be atleast about 0.002 inches greater than the outside diameter of the mainportion of introducer needle 31. It has been surprisingly found thatthis dimension is sufficient, in the context of this invention, toprevent sharp distal tip 32 of introducer needle 31 from being moveddistally out of needle shield 40 after sharp distal tip 32 has beenwithdrawn proximally into needle shield 40. Where enlarged diameterportion 38 is symmetrically disposed about the shaft of introducerneedle 31, preferably the diameter of enlarged diameter portion 38should be about 0.004 inches greater than the diameter of the mainportion of introducer needle 31. To ensure this difference in diameteris achieved, that portion of introducer needle 31 immediately distal todistal portion 38 b can be formed with a slightly increasing taper fromdistal portion 38 b toward the distal end of introducer needle 31. SeeFIG. 3A. Grinding that portion of introducer needle 31 can form thistaper immediately distal of distal portion 38 b.

The lock that prevents unwanted distal movement of sharp distal tip 32of introducer needle 31 out of the distal end of needle shield 40 oncesharp distal tip 32 has been proximally withdrawn into needle shield 40can take many forms. As used herein the phrase “unwanted distal movementof introducer needle 31” means distal movement of introducer needle 31,during normal use of catheter and introducer needle assembly 10 andunder normal circumstances, such that sharp distal tip 32 is notre-exposed from distal opening 45 of needle shield 40 after the lockengages introducer needle 31.

As shown in FIGS. 4 through 7, the lock can be in the form of a springgate 100, which can include a separate biasing mechanism 150, to lockintroducer needle 31 in place in needle shield 40. In this embodimentfor the lock, the discontinuous portion is preferably an enlargeddiameter portion 38.

Spring gate 100 and biasing mechanism 150 are located in cavity 42 ofhousing 41 of needle shield 40 and about introducer needle 31. Springgate 100 has a pair of spaced apart tines 110 connected by a base 120.Tines 110 should define at least one portion having a distancetherebetween that is slightly larger than the diameter of the mainportion of introducer needle 31 and is less than the diameter ofenlarged diameter portion 38. This allows the main portion of introducerneedle 31 to be positioned between tines 110 and move proximally pasttines 110. Base 120 may extend generally perpendicular to tines 110 toprovide more surface area to contact biasing mechanism 150, describedbelow. Although the face of spring gate 100 is shown in the FIGS. ashaving a generally U-shape, it is to be understood that other shapescould be used for the face of spring gate 100 as long as the shapeallows at least one tine 110 to engage enlarged diameter portion 38. Forexample, the face of spring gate 100 could have a V-shape or an L-shape.

Biasing mechanism 150 forces spring gate 100 up into contact withintroducer needle 31 and ensures that tines 110 and base 120 remainadjacent to introducer needle 31. Biasing mechanism 150 may take anyappropriate form. For example, it may be a helical spring as shown inFIGS. 4 through 6, or it may be a compressible rubber-like material thatacts as a spring or it may be configured as a leaf spring. Moreover,biasing mechanism 150 and tines 110 could be integrated as one member.

As introducer needle 31 is withdrawn proximally into needle shield 40,the main portion of introducer needle 31 passes between tines 110. Whenenlarged diameter portion 38 abuts tines 110, spring gate 110 is rotatedproximally and forced downwardly against the bias of biasing mechanism150 by the proximal movement of enlarged diameter portion 38. Thisallows enlarged diameter portion 38 to pass proximally past tines 110.Compare FIGS. 4 and 5. Once enlarged diameter portion 38 is proximal oftines 110, biasing mechanism 150 forces spring gate 100 to rotateclockwise, as seen in the FIGS, back into engagement with introducerneedle 31. When enlarged diameter portion 38 is proximal of tines 110,sharp distal tip 32 is proximal of distal opening 45. See FIG. 6.Similarly, all of the embodiments disclosed herein are configured suchthat sharp distal tip 32 is locked in needle shield 40 proximal ofdistal opening 45.

Subsequent distal movement of introducer needle 31 is prevented by theengagement of enlarged diameter portion 38 and tines 110. Since tines110 engage the distal wall of cavity 42, tines 110 cannot be moveddistally past this distal wall. Thus, if a clinician tries to advanceintroducer needle 31 distally after enlarged diameter portion 38 hasbeen moved proximal of tines 110, enlarged diameter portion 38 wouldbutt up against tines 110 which in turn would butt up against the distalwall of cavity 42. Biasing mechanism 150 ensures that tines 110 remainengaged to introducer needle 31. And as discussed above, furtherproximal movement of introducer needle 31 from needle shield 40 isprevented because enlarged diameter portion 38 blocks further proximalmovement of introducer needle 31 through proximal opening 43 or washer49. Alternatively, a tether 50 connecting needle shield 40 and needlehub 34 could be used to prevent unwanted proximal movement of introducerneedle 31 out of needle shield 40.

A second embodiment for the lock that prevents unwanted distal movementof introducer needle 31 is a leaf spring 200. See FIGS. 8 through 10.Leaf spring 200 has a proximal wall 210 defining an opening 215 thereinaligned with proximal opening 43 of cavity 42. Proximal wall 210 isgenerally perpendicular to the longitudinal axis of introducer needle31. Where enlarged diameter portion 38 is used on introducer needle 31,preferably opening 215 has a diameter at least slightly larger than thediameter of the main portion of introducer needle 31 but smaller thanthe diameter of enlarged diameter portion 38. Of course, it is notnecessary for leaf spring 200 to include proximal wall 210 and opening215 as long as proximal opening 43, washer 49 or tether 50 is used toprevent proximal movement of sharp distal tip 32 out of needle shield40.

Leaf spring 200 also has a support leg 220 and a locking leg 230oriented at an angle to support leg 220 such that locking leg 230 isdirected generally toward proximal wall 210 so that locking leg 230 ispreferably not perpendicular to support leg 220. Preferably, locking leg230 approaches being parallel to support leg 220. As seen in FIGS. 8-10support leg 220 and locking leg 230 are preferably-oriented to eachother such that leaf spring 200 has a generally V-shape lying on itsside, with the apex of the V facing distally. This V-shapedconfiguration ensures that locking leg 230 is biased toward introducerneedle 31 and is oriented at an angle to support leg 220.

Locking leg 230 includes a pair of spaced apart tines 240. Along atleast one portion of tines 240, a distance is defined therebetween thatis slightly larger than the diameter of the main portion of introducerneedle 31 and is less than the diameter of enlarged diameter portion 38.This allows the main portion of introducer needle 31 to extend betweentines 240 and move proximally past tines 240. Tines 240 are preferablyoriented on locking leg 230 so as to assume a generally V-shapedconfiguration.

As introducer needle 31 is withdrawn proximally into needle shield 40,the main portion of introducer needle 31 passes between tines 240. Whenenlarged diameter portion 38 abuts tines 240, they are rotatedcounterclockwise, as seen in the FIGS. This allows enlarged diameterportion 38 to move proximally past tines 240. Once enlarged diameterportion 38 is proximal of tines 240, the bias of leaf spring 200 causeslocking leg 230 and tines 240 to rotate clockwise, as seen in the FIGS.back into engagement with introducer needle 31. If introducer needle 31is subsequently moved distally, locking leg 230 and tines 240 willcontinue to rotate clockwise, as seen in the FIGS. This forcesintroducer needle 31 upwardly into tight engagement with the wallsdefining cavity 42 of needle shield 40 and prevents re-exposure of sharpdistal tip 32. Any subsequent distal movement of introducer needle 31 isprevented and, if enough distally directed force is applied tointroducer needle 31, could cause introducer needle 31 to buckle andpermanently lock introducer needle 31 in needle shield 40. See FIG. 9.

Further proximal movement of introducer needle 31 is prevented by theengagement of enlarged diameter portion 38 with proximal wall 210.Again, if desired, a tether 50 connecting needle shield 40 to needle hub34 could be used to prevent this unwanted proximal movement ofintroducer needle 31 with respect to needle shield 40.

A third embodiment for the lock that prevents unwanted distal movementof introducer needle 31 is a leaf spring 300. See FIGS. 11 through 13.Leaf spring 300 has a proximal wall 310 defining an opening 315 thereinaligned with proximal opening 43 of cavity 42. Proximal wall 310 isgenerally perpendicular to the longitudinal axis of needle shield 40.Where enlarged diameter portion 38 is used on introducer needle 31,preferably the diameter of opening 315 is slightly larger than thediameter of the main portion of introducer needle 31 but smaller thanthe diameter of enlarged diameter portion 38. Of course, it is notnecessary for leaf spring 300 to include proximal wall 310 and opening315 as long as proximal opening 43, washer 49 or tether 50 is used toprevent proximal movement of sharp distal tip 32 out of needle shield40.

Leaf spring 300 also has a support leg 320 and a locking leg 330oriented at an angle to support leg 320 such that locking leg 330 isdirected generally toward proximal wall 310 and is not perpendicular tosupport leg 320. Preferably, locking leg 330 approaches being parallelto support leg 320. As seen in FIG. 11, support leg 320 and locking leg330 are preferably oriented to each other such that leaf spring 300 hasa generally V-shape lying on its side, with the apex of the V facingdistally. This V-shaped configuration ensures that locking leg 330 isbiased toward introducer needle 31. Alternatively locking leg 330 couldbe oriented at a different angle to support leg 320. For example,locking leg 330 could be oriented at an angle to support leg 320 thatapproaches 90 degrees. See FIG. 17 and compare support leg 620 andlocking leg 630. Indeed, locking leg 330 could in fact be perpendicularto support leg 320 or could be oriented anywhere between being parallelto or perpendicular to support leg 320. The main criterion for theconfiguration of leaf spring 300 is to have locking leg 330 biasedtoward introducer needle 31 so it engages enlarged diameter portion 38.

That portion of locking leg 330 that abuts introducer needle 31 can becontoured to form a generally semi-circular cross-section to approximatea portion of the circumference of the main portion of introducer needle31. This minimizes drag on introducer needle 31 as it is being movedproximally past locking leg 330.

In the embodiment of FIGS. 11 through 13, enlarged diameter portion 38shown in FIG. 3A is preferably used. This embodiment includes a taperedproximal portion 38 a and a distal portion 38 b that is generallyperpendicular to the longitudinal axis of introducer needle 31. However,it is to be understood that the other embodiments for the discontinuousportion on introducer needle 31 could be used. In addition, the end oflocking leg 330 that engages the discontinuous portion could beconfigured appropriately to mechanically engage the discontinuousportion. For example, if notch 39 were used as the discontinuousportion, the portion of locking leg 330 that engages notch 39 wouldinclude a tab to engage the notch. See for example, the tab in FIG. 31.

Locking leg 330 rides along the main portion of introducer needle 31 asintroducer needle 31 is withdrawn proximally into needle shield 40.Locking leg 330 also rides over enlarged diameter portion 38 as it ispulled proximally past locking leg 330. Having a tapered proximalportion 38 a facilitates movement of enlarged diameter portion 38 pastlocking leg 330 so enlarged diameter portion 38 is proximal of lockingleg 330. If introducer needle 31 is moved distally after enlargeddiameter portion 38 and distal portion 38 b are moved proximally of theproximal end of locking leg 330, the proximal end of locking leg 330will engage distal portion 38 b and prevent further distal movement ofintroducer needle 31. In addition, such distally directed force appliedto introducer needle 31 will cause locking leg 330 to rotate clockwise,as seen in the FIGS. This forces introducer needle 31 upwardly intotight engagement with the walls defining cavity 42 of needle shield 40and prevents re-exposure of sharp distal tip 32.

Further proximal movement of introducer needle 31 is prevented by theengagement of enlarged diameter portion 38 with proximal wall 310.Again, if desired, a tether 50 connecting needle shield 40 to needle hub34 could be used to prevent this unwanted proximal movement ofintroducer needle 31 with respect to needle shield 40.

A fourth embodiment for the lock that prevents unwanted distal movementof introducer needle 31 is shown in FIGS. 14 and 15. The fourthembodiment is a leaf spring 400 that includes a proximal wall 410supporting a pair of support legs 420 each of which is connected to alocking leg 430. Proximal wall 410 defines an opening 415 thereinthrough which introducer needle 31 can extend. Proximal wall 410,support legs 420 and locking legs 430 are configured so that lockinglegs are biased toward the main portion of introducer needle 31. In thisembodiment, introducer needle 31 preferably includes enlarged diameterportion 38 shown in FIG. 3A. Although as previously discussed, otherembodiments for the discontinuous portion could also be used.

Locking legs 430 can be oriented at a wide range of angles to supportlegs 420. Preferably locking legs 430 are oriented at an angle less than90 degrees to support legs. Regardless of the angle of orientation,locking legs 430 must engage distal portion 38 b in order to preventunwanted distal movement of introducer needle 31.

Locking legs 430 ride along the main portion of introducer needle 31 asintroducer needle 31 is withdrawn proximally into needle shield 40.Locking legs 430 ride over enlarged diameter portion 38 as it is pulledproximally past locking legs 430. Tapered proximal portion 38 afacilitates movement of enlarged diameter portion 38 past locking legs430 so enlarged diameter portion is proximal of locking legs 430. Ifintroducer needle 31 is moved distally after enlarged diameter portion38 and distal portion 38 b are moved proximally of the proximal end oflocking legs 430, the ends of locking legs 430 will engage distalportion 38 b and prevent further distal movement of introducer needle31.

Further proximal movement of introducer needle 31 is prevented by theengagement of enlarged diameter portion 38 with proximal wall 410.Again, if desired, a tether 50 connecting needle shield 40 to needle hub34 could be used to prevent this unwanted proximal movement ofintroducer needle 31 with respect to needle shield 40.

As shown in FIGS. 14 and 15, leaf spring 400 and housing 41 may beconfigured to enhance the mechanical engagement between locking legs 430and enlarged diameter portion 38. This is achieved by allowing leafspring 400 to move distally in cavity 42 after enlarged diameter portion38 has been withdrawn into needle shield 40 proximal of locking legs430. In this embodiment, cavity 42 has a tapered cross section. Thistaper is such that the inner diameter of cavity 42 decreases from itsproximal portion toward its distal portion. This taper should besufficient to engage support legs 420 and force support legs 420 towardintroducer needle 31. Preferably this taper, as defined by the anglebetween the wall of cavity 42 and the longitudinal axis of introducerneedle 31, should be less than 90 degrees minus the static slip anglecreated between the surface of support legs 420 and the wall of cavity42. With this configuration, any subsequent distal movement ofintroducer needle 31 will cause leaf spring 400 to move distally withintroducer needle 31 until support legs 420 engage the tapered walls ofhousing 41. As support legs 420 engage the tapered walls, locking legs430 are forced into tighter contact with the shaft of introducer needle31 and may even bind into the surface of introducer needle 31. Thistight contact between locking legs 430 and distal portion 38 b ensuresthat the force needed to overcome the mechanical engagement between theends of locking legs 430 and distal portion 38 b will be too high for aclinician, using catheter and introducer needle assembly 10 in a normalmanner and in normal circumstances, to overcome.

The fifth embodiment of the lock that prevents unwanted distal movementof introducer needle 31 is a variation of the fourth embodiment of thelock that prevents unwanted distal movement of introducer needle 31 andthat minimizes drag on introducer needle 31 as it is being withdrawn inneedle shield 40. See FIG. 16. The fifth embodiment is a leaf spring 500that includes a proximal wall 510 supporting a pair of support legs 520each of which is connected to a locking leg 530. Proximal wall 510defines an opening 515 therein through which introducer needle 31 canextend. Proximal wall 510, support legs 520 and locking legs 530 areconfigured so that locking legs are biased toward the shaft ofintroducer needle 31. In this embodiment, introducer needle 31preferably includes enlarged diameter portion 38 shown in FIG. 3A.Although as previously discussed, other embodiments for thediscontinuous portion could also be used.

At least one, but preferably each support leg 520 includes a supportfinger 550 thereon. Each support finger 550 cooperates with a supporttab 560 formed on housing 41 to hold each support leg 520 away from theshaft of introducer needle 31. Leaf spring 500 is disposed in cavity 42such that proximal wall 510 is spaced distally from the proximal wall ofcavity 42 to allow proximal movement of leaf spring 500 when introducerneedle 31 is withdrawn into needle shield 40. When enlarged diameterportion 38 engages proximal wall 510 as a result of the proximalmovement of introducer needle 31, leaf spring 500 will be movedproximally with continued proximal movement of introducer needle 31.This allows each support finger 550 to be moved out of engagement withsupport tabs 560, which in turn allows support legs 520 to return totheir inward position. In the inward position, locking legs 530 engagethe main portion of introducer needle 31. Unwanted distal and proximalmovement of introducer needle 31 is prevented in a similar manner as isaccomplished in the fourth embodiment of the lock.

The sixth embodiment of the lock that prevents unwanted distal movementof introducer needle 31 is shown in FIGS. 17 and 18. In this embodiment,the leaf spring 600 includes a proximal wall 610 supporting a pair ofsupport legs 620 each of which is connected to a locking leg 630.Proximal wall 610 defines an opening 615 therein through whichintroducer needle 31 can extend. In this embodiment, it is not necessarythat locking legs 630 be biased toward the shaft of introducer needle31. In fact, in order to minimize drag on the shaft of introducer needle31 as it is moved proximally into needle shield 40, the ends of lockinglegs 630 are preferably spaced away from the shaft of introducer needle31. This allows introducer needle 31 to be easily withdrawn into needleshield 40.

In this embodiment, introducer needle 31 preferably includes enlargeddiameter portion 38 shown in FIG. 3A. Although as previously discussed,other embodiments for the discontinuous portion could also be used.

Cavity 42 has a proximal portion and a distal portion where the diameterof the proximal portion is smaller than the diameter of the distalportion. When sharp distal tip 32 is distal of the distal end of needleshield 40 prior to use in inserting a catheter into a patient, leafspring 600 is located substantially in the distal portion of cavity 42.As introducer needle 31 continues to be moved proximally into needleshield 40, enlarged diameter portion 38 moves proximally of locking legs630 and subsequently engages proximal wall 610 and subsequently pullsleaf spring 600 into the proximal portion of cavity 42. The smallerdiameter for the proximal portion forces support legs 620 and thuslocking legs 630 toward the main portion of introducer needle 31 so thatlocking legs 630 can engage introducer needle 31 distal of but adjacentto enlarged diameter portion 38.

The leaf spring 600 includes at least one, and preferably two, flexibleradially outwardly biased fingers 650 extending from support legs 620.Housing 41 defines a slot 660 for each finger 650 wherein each slot 660has a proximally facing shoulder. As leaf spring 600 is pulledproximally into the proximal portion of cavity 42 by the engagementbetween enlarged diameter portion 38 and proximal wall 610, fingers 650flex inwardly because of their contact with the inner walls of housing41. However, once fingers 650 become aligned with slots 660, fingers 650can return to their outward position and move into slots 660. Theengagement of fingers 650 and the proximally facing shoulder of slot 660prevents any subsequent distal movement of leaf spring 600 with respectto housing 41. When leaf spring 600 is in this position in housing 41,the ends of locking legs 630 abut introducer needle 31 distal of butadjacent to enlarged diameter portion 38. Thus, any unwanted distalmovement of introducer needle 31 is prevented by the engagement of theends of locking legs 630 and distal portion 38 b.

A seventh embodiment for the lock that prevents unwanted distal movementof introducer needle 31 is shown in FIGS. 19 through 21. In thisembodiment, leaf spring 700 includes a proximal wall 710 supporting asupport leg 720, which in turn is connected to a locking leg 730.Proximal wall 710 defines an opening 715 therein through whichintroducer needle 31 can extend. Preferably locking leg 730 issubstantially perpendicular to support leg 720 and defines an opening735 therein. Preferably the diameter of opening 735 is slightly largerthan the diameter of the main portion of introducer needle 31 but issmaller than the diameter of enlarged diameter portion 38. Proximal wall710, support leg 720 and locking leg 730 are configured such thatlocking leg 730 is biased toward introducer needle 31. Of course, theorientation of leaf spring 700 could be at any angle around thelongitudinal axis of introducer needle 31 so that support leg is biasedtoward introducer needle 31.

In this embodiment, introducer needle 31 must include enlarged diameterportion 38. Preferably, enlarged diameter portion 38 shown in FIG. 3C isused.

In the unlocked and biased position for leaf spring 700, sharp distaltip 32 of introducer needle 31 is distal of the distal end of needleshield 40 and locking leg 730 contacts and is biased toward introducerneedle 31. See FIG. 19. As introducer needle 31 is withdrawn proximallyinto needle shield 40 locking leg 730 rides over the surface ofintroducer needle 31. Locking leg 730 can include a proximally ordistally directed tab 738 that contacts introducer needle 31 to minimizedrag on introducer needle 31. Once sharp distal tip 32 of introducerneedle 31 is moved proximal of locking leg 730, leaf spring 700 returnsto its unbiased, i.e. activated, position such that opening 735 issubstantially aligned with the longitudinal axis of introducer needle 31and distal opening 45. If introducer needle 31 is thereafter moveddistally with respect to needle shield 40, sharp distal tip 32 ofintroducer needle 31 extends through opening 735 until enlarged diameterportion 38 engages opening 735. Unwanted distal movement of introducerneedle 31 is thus prevented so that sharp distal tip 32 cannot bere-exposed outside needle shield 40.

Further proximal movement of introducer needle 31 is prevented by theengagement of enlarged diameter portion 38 with proximal wall 710.Again, it is not necessary for leaf spring 700 to include proximal wall710 and opening 715. As long as proximal opening 43, washer 49 or tether50 could be used instead to prevent this unwanted proximal movement ofintroducer needle 31 with respect to needle shield 40.

Locking leg 730 can have a funnel configuration 736 adjacent to opening735. This funnel configuration 736 acts as a guide for introducer needle31 to ensure that it passes through opening 735 if introducer needle 31is moved distally after it has been withdrawn into needle shield 40.Funnel configuration 736 can be configured so that it is complementaryto the shape of the tapered distal portion 38 b of enlarged diameterportion 38 shown in FIG. 3C.

An eighth embodiment of the lock that prevents unwanted distal movementof introducer needle 31 is shown in FIGS. 22 through 25. In thisembodiment, introducer needle 31 must include enlarged diameter portion38. Preferably, enlarged diameter portion 38 shown in FIG. 3C is used.

The lock of this embodiment is a leaf spring 800 that includes aproximal wall 810, a support leg 820 connected to one end of proximalwall 810 and a locking leg 830 connected to support leg 820. Inaddition, leaf spring 800 includes an outwardly biased locking arm 850connected to the other end of proximal wall 810. An opening 815 isdefined in proximal wall 810 and an opening 835 is defined in lockingleg 830. Both openings 815 and 835 allow introducer needle 31 to extendtherethrough. Opening 835 has a diameter slightly larger than thediameter of enlarged diameter portion 38, whereas opening 815 has adiameter smaller than the largest diameter of enlarged diameter portion38.

Cavity 42 of housing 41 defines a proximal portion, a medial portion anda distal portion wherein the diameter of the medial portion is less thanthe diameters of the proximal portion and the distal portion. As aresult of this configuration, cavity 42 defines a proximally facingshoulder 860 and a distally facing shoulder 870. Leaf spring 800 isinitially located in the medial portion of cavity 42 such that lockingleg 830 abuts distally facing shoulder 870. In addition, leaf spring 800is located in the medial portion of cavity 42 such that it is movableproximally with respect to housing 41.

Prior to withdrawal of sharp distal tip 32 into needle shield 40; leafspring 800 is in the position shown in FIG. 22 such that locking leg 830is generally perpendicular to the shaft of introducer needle 31. Asintroducer needle 31 is moved proximally into needle shield 40, enlargeddiameter portion 38 passes through opening 835 of locking leg 830 untilthe proximal end of enlarged diameter portion 38 engages proximal wall810. Since the diameter of opening 815 is less than the largest diameterof enlarged diameter portion 38, continued relative proximal movement ofintroducer needle 31 with respect to leaf spring 800 is prevented.However, continued proximal movement of introducer needle 31 causes leafspring 800 to move proximally until proximal wall 810 abuts against theproximal wall of cavity 42. At this point, further proximal movement ofintroducer needle 31 and leaf spring 800 is prevented.

Since locking leg 830 abuts distally facing shoulder 870 in housing 41,the proximal movement of leaf spring 800 with respect to housing 41causes locking leg 830 to rotate. As such the orientation of locking leg830 with respect to introducer needle 31 changes so locking leg 830 isno longer perpendicular to introducer needle 31. Compare FIGS. 22 and23. In addition, the proximal movement of leaf spring 800 causes lockingarm 850 to become aligned with the larger diameter proximal portion ofcavity 42. This allows locking arm 850 to move to its outward position,away from introducer needle 31 into the proximal portion of cavity 42 sothat locking arm 850 abuts proximally facing shoulder 860. In thisposition, any subsequent distal movement of leaf spring 800 with respectto housing 41 is prevented.

When locking leg 830 is no longer perpendicular to introducer needle 31,opening 835 is skewed with respect to enlarged diameter portion 38.Thus, in this orientation, the effective diameter of opening 835 is lessthan the diameter of enlarged diameter portion 38 and is approximatelyequal to the diameter of the main portion of introducer needle 31. Asused herein, the term “effective diameter” means the diameter of theimage of opening 835 when it is projected onto a plane perpendicular tothe longitudinal axis of introducer needle 31. Because, the effectivediameter of opening 835 is less than the diameter of enlarged diameterportion 38 in the orientation shown in FIGS. 23 and 25, enlargeddiameter portion 38 is prevented from moving distally past locking leg830 and sharp distal tip 32 is effectively locked in needle shield 40.Indeed, as introducer needle 31 is moved distally, the binding forcebetween locking leg 830 and introducer needle 31 increases making itextremely difficult for enlarged diameter portion 38 to be moveddistally past locking leg 830 and thus defeat this lock.

A ninth embodiment of the lock that prevents unwanted distal movement ofintroducer needle 31 is shown in FIGS. 26 through 28 and is a tube 900.In this embodiment, the discontinuous portion on introducer needle 31 ispreferably an enlarged diameter portion. Even more preferably, enlargeddiameter portion 38 shown in FIG. 3A is used although other embodimentsfor enlarged diameter portion 38 could be used.

Tube 900 is located in cavity 42 and includes at least one movablelanced tab 950 that extends inwardly into tube 900 in a proximaldirection. Preferably two such tabs 950 are formed on opposite sides oftube 900. The distal portion of tube 900 has an inner diameter greaterthan the diameter of enlarged diameter portion 38 to allow introducerneedle 31 freely to move therein. Because tabs 950 are movable, enlargeddiameter portion 38 can move past the proximal ends of tabs 950 asintroducer needle 31 is withdrawn proximally into needle shield 40.Again the proximal movement of introducer needle 31 past tabs 950 isfacilitated by tapered proximal portion 38 a. Once introducer needle 31has been withdrawn proximally into needle shield 40 such that tabs 950are distal of distal portion 38 b, any unwanted distal movement ofintroducer needle 31 will be prevented by the engagement of the proximalends of tabs 950 with enlarged diameter portion 38. Further proximalmovement of introducer needle 31 is prevented by the engagement ofenlarged diameter portion 38 with proximal opening 43. Alternatively,the proximal portion of tube 900 could be formed with an inner diametersmaller than the diameter of enlarged diameter portion 38 to preventunwanted proximal movement of introducer needle out of tube 900. Inaddition, washer 49 or tether 50 could be used to prevent unwantedproximal movement.

A tenth embodiment of the lock that prevents unwanted movement ofintroducer needle 31 is shown in FIGS. 29 through 32. This lock is aspeed nut 1000, which defines a through hole 1010 that has a diameterslightly larger than the diameter of the main portion of introducerneedle 31. This allows introducer needle 31 to extend through speed nut1000. Speed nut 1000 includes at least one but preferably a plurality ofmovable tabs 1020 extending from the main body portion 1030 of speed nut1000. Tabs 1020 are biased toward introducer needle 31 so they areproximally oriented and extend inwardly toward the proximal end ofintroducer needle 31. The distal ends of tabs 1020 are connected to mainbody portion 1030 of speed nut 1000 by, for example, a living hinge. SeeFIG. 32.

Because tabs 1020 are proximally oriented and movable, enlarged diameterportion 38 can move easily past the proximal ends of tabs 1020 asintroducer needle 31 is withdrawn proximally into needle shield 40. Onceintroducer needle 31 has been withdrawn proximally into needle shield 40such that tabs 1020 are distal of enlarged diameter portion 38, unwanteddistal movement of introducer needle 31 will be prevented by theengagement of the proximal ends of tabs 1020 with distal portion 38 b ofenlarged diameter portion 38. The generally proximal orientation of tabs1020 also causes tabs 1020 to bite into the surface of introducer needle31 to hold introducer needle 31 in place. Further proximal movement ofintroducer needle 31 is prevented by the engagement of enlarged diameterportion 38 with proximal opening 43 or washer 49. Again, proximalopening 43, washer 49 or tether 50 could be used to prevent thisunwanted proximal movement.

As shown in FIG. 31, the discontinuous portion of introducer needle 31can be in the form of a notch 39 such as shown in FIGS. 3E, 3F and 3G.When introducer needle 31, and thus notch 39, is withdrawn through speednut 1000, at least one tab 1020 will drop into notch 39. Any subsequentdistal movement of introducer needle 31 will be prevented by theengagement of tab 1020 with the distally facing portion, i.e. theproximal edge, of notch 39. The use of a plurality of tabs 1020 formedaround main body portion 1030 ensures that at least one tab 1020 willengage notch 39. Alternatively, a plurality of longitudinally displacenotches 39 located about the circumference of introducer needle 31 couldbe used to catch tabs 1020.

When a notch 39 is used as the discontinuous portion on introducerneedle 31, such as shown in FIG. 3D, instead of an enlarged diameterportion 38, a tether 50 connecting needle shield 40 to needle hub 34 maybe used to prevent unwanted proximal movement of introducer needle 31with respect to needle shield 40. Also, as described herein, tether 50is a mechanism to prevent introducer needle 31 from being withdrawnproximally out of the proximal portion of needle shield 40 instead ofthe engagement of enlarged diameter portion 38 with proximal opening 43or washer 49.

An eleventh embodiment of the lock that prevents unwanted distalmovement of introducer needle 31 is shown in FIGS. 33 through 35, 37A,37B and 37C. In this embodiment, the lock is a retention plate 1100,which includes tabs 1120 that do not extend proximally from the mainportion of retention plate 1100. See specifically FIG. 37A. However,tabs 1120 are still connected to the main portion of retention plate1100 via any appropriate mechanism, such as a living hinge, so that tabs1120 are movable with respect to the main portion of retention plate1100. Tabs 1120 define a through hole 1130 between the ends of each tab1120 that has a diameter slightly greater than the diameter of the mainportion of introducer needle 31 but is smaller than the diameter ofenlarged diameter portion 38. Retention plate 1100 is located adjacentto the proximal face of a medial wall 1140 formed in cavity 42 ofhousing 41. Medial wall 1140 defines an opening 1145 therethrough thathas a diameter greater than the diameter of enlarged diameter portion38.

As introducer needle 31 is moved proximally into needle shield 40,enlarged diameter portion 38 can pass through opening 1145. In addition,enlarged diameter portion 38 can move past tabs 1120 since tabs 1120will move proximally out of the way of enlarged diameter portion 38.However, once enlarged diameter portion 38 is moved proximal ofretention plate 1100, any subsequent distal movement of introducerneedle 31 with respect to needle shield 40 is prevented. This is becauseenlarged diameter portion 38 can not extend back through hole 1130 butinstead engages the surface of tabs 1120 adjacent to hole 1130. Inaddition, tabs 1120 cannot move distally out of the way of enlargeddiameter portion 38 because medial wall 1140 prevents any such distalmovement of tabs 1120. Any further proximal movement of introducerneedle 31 is prevented by proximal opening 43, washer 49 or tether 50.

FIGS. 37B and 37C show variations of the retention plate shown in FIG.37A. In both of these variations, tabs 1120 include distally extendingfingers adjacent to hole 1130 such as to define the diameter of hole1130. Fingers 1101 are shown in FIG. 37B and fingers 1101′ are shown inFIG. 37C. In FIG. 37C, the outer portions of fingers 1101′ are taperedso they slope toward introducer needle 31 in the distal direction andthe inner walls defining opening 1145 have a complementary slope.Fingers 1101 and 1101′ fill any excess space in opening 1145 in medialwall 1140 and ensure that unwanted distal movement of introducer needle31. In the case of the variation shown in FIG. 37C, fingers 1101′provide a greater holding force to introducer needle 31 to preventunwanted distal movement of introducer needle 31. This is because asintroducer needle 31 is moved distally after enlarged diameter portion38 has been moved proximal of retention platel 100, fingers 1101′ willwedge into opening 1145 making it significantly more difficult to moveintroducer needle 31 distally.

FIGS. 33 through 36C, 38 and 39 show a first embodiment of a resilientspring clip 1201 that is used to connect needle shield 40 to catheterhub 24 until sharp distal tip 32 of introducer needle 31 has beenwithdrawn into needle shield 40. A spring arm 151 that is formed in aV-shaped configuration defines the spring clip. Spring arm 151 isdisposed in housing 41 such that the apex of the V is pointed up towardthe top of housing 41 and the legs defining the V straddle thelongitudinal axis of introducer needle 31 when spring arm 151 is in itsunbiased position. In this orientation, spring arm 151 is adapted formotion transverse to the longitudinal axis of introducer needle 31. Thismotion is along a defined path provided by a ramped surface 159 inhousing 41. See FIGS. 38 and 39.

Of course spring arm 151 could be disposed in housing 41 such that theapex is oriented in other positions on a circle concentric to thelongitudinal axis of introducer needle 31. All that is required is thatspring arm 151 be adapted for motion transverse to the longitudinal axisof introducer needle 31. The apex of the V shape facilitates the flexingof spring arm 151 to and from a biased condition. In addition, the apexof the V shape could be in the form of a living hinge.

When sharp distal tip 32 of introducer needle 31 is distal of needleshield 40, introducer needle 31 abuts spring arm 151 so as to holdspring arm 151 in the biased, unactivated, clipped position. Spring arm151 includes a clip arm 152 which extends generally parallel to thelongitudinal axis of introducer needle 31. Clip arm 152 preferably has afinger 153 formed thereon, which is adapted to engage thread 44 or acorresponding detent 26 formed on catheter hub 24 when spring arm 151 isin the clipped position. Detent 26 can be the flange or luer lockingears 44 shown on the proximal end of catheter hub 24. Alternatively,detent 26 can take the form of a notch or slot, or an upstanding peg.Although the use of finger 153 and detent 26 is preferred because itprovides positive mechanical engagement therebetween, these elements arenot necessary. Without any detents the engagement force between clip arm152 and catheter hub 24 is limited to frictional force which may beeasier to overcome than with mechanical engagement. However, in certainsituations, this frictional force may be sufficient.

When sharp distal tip 32 of introducer needle 31 is moved proximallyinto needle shield 40 so that introducer needle 31 no longer abutsspring arm 151, spring arm 151 can flex to its unbiased, activatednon-clipped position out of engagement with catheter hub 24. This allowscatheter hub 24 to be disconnected from needle shield 40. Spring arm 151may include a longitudinally extending flag 158 that minimizes drag onintroducer needle 31, and enlarged diameter portion 38 if any, asintroducer needle 31 is being moved proximally into needle shield 40. Inaddition, spring arm 151 may include an arm 53 extending therefrom andwhich defines an opening therein. In one embodiment, arm 53 alsoincludes a longitudinally extending guide rail 51 that guides introducerneedle 31 toward opening 52. See FIG. 36B. The diameter of opening 52 isslightly greater than the diameter of the main portion of introducerneedle 31 but is smaller than the diameter of enlarged diameter portion38. Thus spring clip 151 can work to prevent unwanted distal movement ofintroducer needle 31 in a similar manner to the leaf spring 700 shown inFIGS. 19-21. In an alternative embodiment, a tapered opening 54 can beused instead. See FIG. 36. All that is required is for opening 54 todefine a portion that allows the main portion of introducer needle 31 toextend therethrough and to define a portion that does not allow theenlarged diameter portion 38 to extend therethrough.

It is to be understood that the various embodiments of the resilientspring clips discussed hereinafter can be used in conjunction with anyof the previous embodiments of the lock that prevents unwanted distalmovement of sharp distal tip 32 of introducer needle 31 out of thedistal end of needle shield 40 once sharp distal tip 32 has beenproximally withdrawn into needle shield 40. Preferably, the resilientspring clips are formed from stainless steel. However, it is to beunderstood that other flexible, strong materials could also be used toform the resilient spring clips.

As previously mentioned, the V-shaped configuration of spring arm 151ensures that it can flex between a clipped, i.e. a biased and anunactivated, position and a non-clipped, i.e. an unbiased and anactivated, position. In the unactivated position, finger 153 ispositioned into engagement with catheter hub 24. See FIG. 34. In theactivated position, finger 153 is not in engagement with catheter hub24. See FIG. 35. Preferably, housing 41 defines a ramp 159 extendingtransversely to the longitudinal axis of introducer needle 31. See FIGS.38 and 39. Ramp 159 is located in housing 41 such that it engages cliparm 152. Ramp 159 acts as a guide for clip arm 152 to ensure clip arm152 and finger 153 do not rotate around catheter hub 24 but instead movetransversely to the longitudinal axis of introducer needle 31 once sharpdistal tip 31 is withdrawn proximally of spring arm 151 out ofengagement with catheter hub 24.

Although this V-shaped configuration for spring clip 1201 is preferred,many different configurations may be used. All that is required is thatthe orientation allows spring arm 151 to flex so clip arm 152 and finger153 can be moved into engagement with catheter hub 24 and can move to anactivated position out of engagement with catheter hub 24.

A first embodiment of a spring clip 1211 with a transverse barrier canbe seen in FIGS. 40 and 41. Spring clip 1211 is formed from spring arm191 and clip arm 192. In this embodiment, spring arm 191 is a resilient,substantially straight and unbent member. Clip arm 192 defines a hole195 through which introducer needle 31 extends. Spring arm 191 isoriented generally perpendicular to introducer needle 31 such that theends of spring arm 191 are fixed to housing 41. Thus, in the unbiased,i.e. activated non-clipped position, hole 195 is not longitudinallyaligned with introducer needle 31. See FIG. 41. Although the FIGS. showintroducer needle 31 above spring arm 191, it is to be understood thatintroducer needle 31 could be below spring arm 191 and spring arm 191could be located within housing 41 such that it extends across thediameter, in any orientation, of a circle concentric to the longitudinalaxis of introducer needle 31.

When introducer needle 31 extends through hole 195 and past the distalend of needle shield 40 and into catheter hub 24, spring arm 191 abutsintroducer needle 31 and is prevented from moving out of engagement withcatheter hub 24. See FIG. 40. Clip arm 192 preferably extendsperpendicular to spring arm 191 and includes a finger 193 formedthereon. In addition, catheter hub 24 also includes a detent 26 thereonfor engagement with finger 193. As discussed above, detent 26 can be aflange or luer locking ears on the proximal end of catheter hub 24.Alternatively, detent 26 can take the form of a notch or slot, or anupstanding peg. When introducer needle 31 extends past spring arm 191,finger 193 engages a detent 26 on catheter hub 24 to maximize theretention force between clip arm 192 and catheter hub 24. Thus, as longas introducer needle 31 extends distally past spring arm 191, clip arm192 and detent 26 remain engaged so catheter hub 24 stays connected withneedle shield 40. Once sharp distal tip 32 of introducer needle 31 iswithdrawn proximally past spring arm 191, clip arm 192 returns to itsactivated, unbiased, non-clipped position so that finger 193 can moveout of engagement with detent 26. This allows catheter hub 24 to beseparated from needle shield 40.

Spring clip 1211 of this embodiment also includes a transverse barrier196, which extends perpendicular to an below spring arm 191 to preventunwanted distal movement of introducer needle 31. Thus when sharp distaltip 32 is moved proximally past spring arm 191, transverse barrier 196acts as a positive barrier to engage sharp distal tip 32 of introducerneedle 31 to prevent unwanted distal movement of introducer needle 31.With this embodiment, no discontinuous portion 38 is needed onintroducer needle 31 and a tether 50 may be used to prevent unwantedproximal movement of introducer needle 31.

However, if desired, discontinuous portion 38 could be used onintroducer needle to prevent unwanted distal movement of introducerneedle 31. In that case, transverse barrier 196 could be formed with anopening 199 therein having a diameter smaller than the diameter ofenlarged diameter portion 38. Opening 199 thus would prevent unwanteddistal movement of introducer needle 31 similar to leaf spring 700 shownin FIGS. 19-21. Indeed, all of the transverse barriers discussed hereincould be modified if desired to include an opening therein that wouldnot allow enlarged diameter portion 38 to pass therethrough.

Although the foregoing embodiments of the spring clips engage theoutside of catheter hub 24, it is to be understood that the spring clipsand introducer needle 31 could be arranged such that the spring clipsengage the inside of catheter hub 24. For example, the spring clipscould be arranged with respect to introducer needle 31 so thatintroducer needle 31 pushes the locking arms radially outwardly. Oncesharp distal tip 32 of introducer needle 31 is moved proximally past thespring arms, they return to their unbiased position and move the lockingarms inwardly toward the longitudinal axis of needle shield 40.

FIGS. 42 through 45 show a second embodiment of a spring clip 1212 witha transverse barrier that connects catheter hub 24 to needle shield 40until sharp distal tip 32 has been locked in needle shield 40. Springclip 1212 of this embodiment is substantially the same as the embodimentfor the spring clip shown in FIGS. 33 through 36C, 38 and 39 except forthe addition of transverse barrier 296. Thus this embodiment of springclip 1212 functions to connect catheter hub 24 to needle shield 40 untilsharp distal tip 32 has been locked in needle shield 40 in substantiallythe same way as the embodiment shown in FIGS. 33 through 36C, 38 and 39.

When introducer needle 31 extends through needle shield 40 so that sharpdistal tip 32 is distal of distal opening 45, spring arm 291 abuts theshaft of introducer needle 31 and is biased to move transverse barrier296 in front of sharp distal tip 32. Once sharp distal tip 32 is movedproximally past spring arm 291, spring arm 291 moves to its activated,unbiased, non-clipped position so that transverse barrier 296 is infront of sharp distal tip 32. This prevents any unwanted distal movementof introducer needle 31.

Where transverse barrier 296 is used, preferably a tether 50 is used toconnect needle shield 40 to needle hub 34. Tether 50 prevents unwantedproximal movement of introducer needle 31 with respect to needle shield40. Tether 50 can take many different forms such as a string, a pleatedelement, a sleeve member surrounding introducer needle 31 or a pluralityof telescoping members surrounding introducer needle 31. Alternatively,where transverse barrier 296 is used, unwanted proximal movement ofintroducer needle 31 can be prevented in the same manner as theembodiments previously discussed. As such, introducer needle 31 can beformed with enlarged diameter portion 38, which would abut proximalopening 43 or washer 49.

Where enlarged diameter portion 38 is used on introducer needle 31,spring clip 1212 could be formed as shown in FIG. 36B or 36C. Asdiscussed above, in those embodiments, the spring clip is formed with anarm 53 extending therefrom similarly to transverse barrier 296. However,arm 53 defines an opening 52 or 54 therein. Opening 54 is tapered from alarger diameter portion to a smaller diameter portion. In both cases,opening 52 and 54 define a portion that has a diameter that is smallerthan the diameter of enlarged diameter portion 38. Thus, after springclip 1212 moves to the non-clipped position, opening 52 and 54 will besubstantially aligned with introducer needle 31. However, unwanteddistal movement of introducer needle 31 will be prevented because thesmaller diameter portion of opening 52 and 54 will prevent the passageof enlarged diameter portion 38 therethrough. Similarly, opening 199shown in the embodiment of FIG. 45 can cooperate with enlarged diameterportion 38 to prevent unwanted distal movement of introducer needle 31.

A first embodiment of an integrated clip lock 1221 that connects needleshield 40 to catheter hub 24 and that prevents unwanted distal movementof sharp distal tip 32 of introducer needle 31 is shown in FIGS. 46through 49. In this embodiment, integrated clip lock 1221 is formed witha spring arm 2191 having a substantially U-shaped configuration with twolegs 2192 wherein the base of legs 2192 is formed as the retention plateshown in FIG. 37A. Spring arm 2191 is configured such that it is biasedoutwardly and can flex into and out of engagement with catheter hub 24.Preferably, spring arm 2191 is oriented in housing 41 such that the baseof the U is oriented toward the proximal portion of needle shield 40 andlegs 2192 are oriented generally parallel to the longitudinal axis ofintroducer needle 31. As discussed in connection with other embodiments,integrated clip lock 1221 could have a single leg and a substantiallyL-shaped configuration. See for example FIGS. 55 through 57. Extendingradially inwardly from each leg 2192 is a biasing arm 2193. A hole 2194is defined in each biasing arm 2193 to allow introducer needle 31 toextend therethrough. If desired, a flap 2199 is located adjacent to eachhole 2194 extending generally parallel to introducer needle 31. Theseflaps 2199 could take the form of turned ends on the biasing arms 2193or the cut out flap portion of biasing arms 2193 that are cut to formholes 2194. Flaps 2199 minimize drag on introducer needle 31 as it iswithdrawn proximally into needle shield 40 through holes 2194.

In addition, the distal portion of each leg 2192 defines a hole 2195therethrough. Holes 2195 are adapted to engage detent 26 formed on theproximal end of catheter hub 24. As discussed above, detent 26 can haveany suitable configuration and the distal portion of each leg 2192 couldlikewise have any complementary configuration so detent 26 and thedistal portion of each leg 2192 could be engaged.

When sharp distal tip 32 of introducer needle 31 extends past the distalend of needle shield 40 into catheter hub 24, introducer needle 31 alsoextends through holes 2194 of biasing arms 2193. This pulls legs 2192inwardly toward catheter hub 24 so holes 2195 engage detent 26. Thismaintains needle shield 40 connected to catheter hub 24 as long as sharpdistal tip 32 of introducer needle 31 is distal of biasing arms 2193.Once introducer needle 31 is pulled proximal of biasing arms 2193, legs2192 are free to return to their unbiased, activated, non-clippedposition where holes 2195 no longer engage detent 26. Thus, spring arm2191 can flex into and out of engagement with catheter hub 24.

Discontinuous portion 38 on introducer needle 31 interacts with theproximal wall as discussed above to prevent unwanted proximal movementof introducer needle 31 and with retention plate 1100 to preventunwanted distal movement of introducer needle 31.

Alternatively, where it is desired to omit discontinuous portion 38 fromintroducer needle 31 one of the biasing arms could be formed with anextended portion that acts as a transverse barrier. See FIG. 50. In thisthird embodiment of the spring clip 1213 having a transverse barrierthat connects catheter hub 24 to needle shield 40 until sharp distal tip32 has been locked in needle shield 40, the transverse barrier 396prevents subsequent distal movement of introducer needle 31 once sharpdistal tip 32 is withdrawn proximally of biasing arms 393. In addition,in this embodiment, a tether 50 would have to be used to connect needleshield 40 and needle hub 34 together to prevent unwanted proximalmovement of introducer needle 31 with respect to needle shield 40 oncesharp distal tip 32 is withdrawn into needle shield 40. This embodimentof spring clip 1213 operates in substantially the same manner as thespring clip portion of integrated clip lock 1221 shown in the previousembodiment of FIGS. 46-49.

As with the previous embodiment, each biasing arm 393 preferably has aflap 399 located adjacent to holes 394 extending generally parallel tointroducer needle 31. Flaps 399 minimize drag on introducer needle 31 asit is withdrawn proximally into needle shield 40 through holes 394.

A fourth embodiment of spring clip 1214 having a transverse barrier thatconnects catheter hub 24 to needle shield 40 until sharp distal tip 32has been locked in needle shield 40 is shown in FIGS. 51 through 53.This embodiment for spring clip 1214 operates in substantially the sameway as the embodiment shown in FIG. 50. The only difference is that theends of biasing arms 493 are formed with interlocking fingers 497. Thesefingers 497 facilitate the locking of each biasing arm 493 to oneanother once sharp distal tip 32 of introducer needle 31 is withdrawnproximally behind biasing arms 493. Preferably, one of biasing arms 493includes two spaced fingers 497 extending from the end of that biasingarm while the other biasing arm includes one finger 497 extendingtherefrom. The one finger is adapted to extend through the space createdby the two fingers on the first biasing arm and the two fingers extendinto the space on either side of the one finger on the second biasingarm. When introducer needle 31 no longer engages biasing arms 493, theends of biasing arms 493 move apart so that fingers 497 can extend intotheir respective spaces and overlap with appropriate portions of eachother and biasing arms 493. With biasing arms 493 thus locked togethervia interlocking fingers 497, a transverse barrier is thereby formed byinterlocking fingers 497 to prevent unwanted distal movement ofintroducer needle 31.

A second embodiment of integrated clip lock 1222 that connects needleshield 40 to catheter hub 24 until sharp distal tip 32 of introducerneedle 31 is locked in needle shield 40 and that prevents unwanteddistal movement of introducer needle 31 is shown in FIG. 54. Thisembodiment is substantially the same as the embodiment of integratedclip lock 1221 shown in FIGS. 46 through 49 except that in thisembodiment a mechanism is provided to minimize drag on introducer needle31. In this embodiment, holes 2294 are maintained in alignment by a pin2280 extending through separate holes formed in biasing arms 2293. Thispin and hole arrangement maintains holes 2294 in alignment without theedges of holes 2294 contacting the shaft of introducer needle 31. Atether 2285 connects pin 2280 with needle hub 34. Tether 2285 has alength such that when introducer needle 31 has been moved proximally sosharp distal tip 32 of introducer needle 31 is proximal of biasing arms2293, tether 2285 pulls pin 2280 proximally out of biasing arms 2293. Atthat point, biasing arms 2293 can move outwardly out of engagement withcatheter hub 24.

A third embodiment of an integrated clip lock 1223 is shown in FIGS. 55through 57. In this embodiment of integrated clip lock 1223, theresilient spring arm 2391 is formed with only one leg 2392 such that itwould have a substantially L-shaped configuration. Preferably spring arm2391 is oriented in housing 41 such that the base is oriented toward theproximal portion of housing 41 and leg 2392 extends generally parallelto the longitudinal axis of introducer needle 31. With only one leg2392, only one biasing arm 2393 needs to be used. Biasing arm 2393defines a hole therein through which introducer needle 31 extends. Thisembodiment for spring arm 2391 operates in a similar manner to theembodiment shown in FIGS. 46 through 49 and the distal portion of leg2392 can have the same configuration of legs 2192. When introducerneedle 31 extends through the hole in biasing arm 2393, leg 2392 ispulled inwardly toward and engages catheter hub 24 as long as sharpdistal tip 32 of introducer needle 31 is distal of biasing arm 2393.Once introducer needle 31 is pulled proximal of biasing arms 2393, leg2392 is free to return to its activated, unbiased, non-clipped position.Thus spring arm 2391 can flex into and out of engagement with catheterhub 24.

A fifth embodiment of spring clip 1215 with a transverse barrier 596 isshown in FIG. 58. In this embodiment, the spring arm 591 is formed withonly one leg 592 such that it has a substantially L-shapedconfiguration. With only one leg 592, only a single biasing arm 593 isused. This single biasing arm 593 is formed with an extended portionthat acts as a transverse barrier 596 to prevent subsequent distalmovement of introducer needle 31 once sharp distal tip 32 is withdrawnproximally of biasing arms 593. This embodiment of spring clip 1215operates in substantially the same manner as the spring clip portion ofintegrated clip lock 1223 shown in FIGS. 55-57.

A sixth embodiment of spring clip 1216 having a transverse barrier isshown in FIGS. 59 through 61. In this embodiment, spring clip 1216 isformed with a pair of crossed legs 692 to provide a substantiallyX-shaped configuration. Spring clip 1216 is preferably oriented inhousing 41 such that base 691 is oriented toward the proximal portion ofhousing 41. Each leg 692 defines a cut-out portion or opening 694therein. These cut-out portions 694 allow introducer needle 31 to extendtherethrough and provide a mechanism to allow legs 692 to cross eachother. The distal portion of each leg 692 is biased inwardly and definesa peg 690 thereon. Pegs 690 are adapted to engage a detents 26 formed onthe inside of catheter hub 24. When introducer needle 31 extends pastthe distal end of needle shield 40 into catheter hub 24, introducerneedle 31 also extends through cut-out portions 694. This pushes legs692 outwardly toward catheter hub 24 so pegs 690 engage detents 26. Thismaintains needle shield 40 connected to catheter hub 24. Once introducerneedle 31 is pulled proximal of cut-out portions 694, legs 692 are freeto return to their inward unbiased, non-clipped position where pegs 690no longer engage detent 26. Thus spring clip 1216 can flex into and outof engagement with catheter hub 24.

A tether 50 could be used in conjunction with spring clip 1216 toprevent unwanted proximal movement of introducer needle 31.Alternatively, the proximal wall 691 of spring clip 1216 could be formedas the retention plate shown in FIG. 37A. Thus, introducer needle 31could be formed with enlarged diameter portion 38 and would cooperatewith the retention plate in the manner previously discussed to preventunwanted distal movement of introducer needle 31.

As discussed above, the configuration of the portion of the spring clipin all of the previous embodiments that engage catheter hub 24, as wellas detent 26, could have a wide variety of configurations. For example,detent 26 could be in the form of a slot and a radially inwardlyextending finger could be disposed on the portion of the spring clipthat engages detent 26. See FIG. 62. Alternatively, detent 26 could bein the form of a post, which could be rectangular or have some othergeometric shape, and holes, which could be open ended, could be formedon the portion of the spring clip that engages detent 26. See FIG. 63.In addition, the configuration of the holes in the biasing arms thatengage the introducer needle could be open ended such as shown in FIGS.64 and 65.

A second embodiment for spring clip 1202 that connects needle shield 40to catheter hub 24 is shown in FIGS. 66 through 69. In this embodiment,spring clip 1202 is formed as a separate piece from retention plate 1100shown in FIG. 37. Spring clip 1202 is formed with a spring arm 251 and apair of outwardly biased clip arms 252. Spring arm 251 is oriented inhousing 41 such that the legs of the U straddle the longitudinal axis ofintroducer needle 31. Preferably the closed portion of the U is orientedtoward the top of housing 41. However, it is to be understood thatspring arm 251 could be in any rotational orientation in the same planeas a circle concentric to the longitudinal axis of introducer needle 31.Each clip arm 252 extends generally parallel to the longitudinal axis ofintroducer needle 31. Of course it is to be understood that only oneclip arm 252 need be used. A biasing arm 253 extends from each end ofspring arm 251. Biasing arms 253 are generally perpendicular to thespring arm 251 and the longitudinal axis of introducer needle 31. Eachbiasing arm 253 defines a hole 254 therethrough to allow introducerneedle 31 to extend therethrough. Each clip arm 252 defines a hole 255adjacent to their distal end. Holes 255 are adapted to engage detent 26formed on the proximal end of catheter hub 24. When introducer needle 31extends past the distal end of needle shield 40 into catheter hub 24,introducer needle 31 also extends through holes 254. This pulls biasingarms 253 together and thus pulls clip arms 252 inwardly toward catheterhub 24 so holes 255 engage detents 26. This maintains needle shield 40connected to catheter hub 24. Once introducer needle 31 is pulledproximal of biasing arms 253, spring arm 251 returns to its unbiasednon-clipped position where clip arms 252 are released from catheter hub24 so that holes 255 no longer engage detent 26. Of course as discussedabove, the configuration of the distal ends of clip arms 252 and detent26 could be changed. For example, detent 26 could be rectangular or havesome other geometric shape. Alternatively, detent 26 could be a slot anda radially inwardly extending finger could be disposed on the distal endof clip arms 252 to mechanically engage detent 26. The operation ofretention plate 1100 is the same as discussed above with the embodimentof FIG. 37.

A seventh embodiment for the spring clip 1217 with a transverse barrierthat prevents unwanted distal movement of introducer needle 31 oncesharp distal tip 32 of introducer needle 31 has been proximallywithdrawn into needle shield 40 is shown in FIGS. 70 through 73. In thisembodiment, no enlarged diameter portion 38 is needed on introducerneedle 31. Instead, spring clip 1217 includes a transverse barrier 796that engages sharp distal tip 32 of introducer needle 31 to preventunwanted distal movement of introducer needle 31. When introducer needle31 extends through needle shield 40 so that sharp distal tip 32 isdistal of distal opening 45, introducer needle 31 also extends throughholes 794. This pulls biasing arms 798 together and thus pulls clip arms792 adjacent to catheter hub 24. Once sharp distal tip 32 is movedproximally behind holes 794, spring arm 791 moves to its unbiased,non-clipped position so that transverse barrier 796 is in front of sharpdistal tip 32. This prevents any subsequent unwanted distal movement ofintroducer needle. Of course, biasing arms 798 could be formed withinterlocking fingers as disclosed in the embodiment of FIGS. 51 through53.

Using tether 50 to connect needle shield 40 with needle hub 34 preventsunwanted proximal movement of introducer needle 31 with respect toneedle shield 40. As discussed above, tether 50 can take many differentforms such as a string, a pleated element, a sleeve member surroundingintroducer needle 31 or a plurality of telescoping members surroundingintroducer needle 31.

An eighth embodiment for spring clip 1218 having a transverse barrierthat connects needle shield 40 to catheter hub 24 until sharp distal tip32 is shielded in needle shield 40 is shown in FIGS. 74 and 75. In thisembodiment, spring clip 1218 includes a clip arm 892 that is pivotallyconnected to needle shield 40. Clip arm 892 includes a finger 899 formechanically engaging flange 44 of catheter hub 24. With this eighthembodiment of spring clip 1218, a leaf spring with a transverse barrier896 to engage sharp distal tip 32 of introducer needle 31 is used toprevent unwanted distal movement of introducer needle 31. In theposition shown in FIG. 74, transverse barrier 896 is held in its outwardposition by the engagement of the end of transverse barrier 896 with theshaft of introducer needle 31. This holds spring clip 1218 in theclipped position. When introducer needle 31 is retracted, transversebarrier 896 is no longer constrained by the shaft of introducer needle31 and thus moves inward. In this position, transverse barrier 896 isdistal of sharp distal tip 32 and thus locks introducer needle 31 inneedle shield 40. Since transverse barrier 896 is no longer holding cliparm 892 in position, it can rotate out of engagement with catheter hub24. See FIG. 75. Thus, catheter hub 24 can be removed from needle shield40. Of course it is to be understood that spring clip 1218 of thisembodiment also may be used in conjunction with the leaf springdisclosed in FIGS. 19 through 21. All that is required is a mechanism torotate clip arm 892 into and out of position with respect to catheterhub 24.

Another embodiment for spring clip 799 that connects needle shield 40 tocatheter hub 24 until sharp distal tip 32 is shielded in needle shield40 is shown in FIGS. 76 and 77. The lock for preventing unwanted distalmovement of introducer needle 31 can be the embodiment shown in FIGS. 19through 21. When sharp distal tip 32 of introducer needle 31 is distalof the distal end of needle shield 40, locking leg 730 contacts and isbiased toward introducer needle 31 and spring clip 799, which acts as ahook, engages flange 44 of catheter hub 24. See FIG. 76. As introducerneedle 31 is withdrawn proximally into needle shield 40 locking leg 730rides over the surface of introducer needle 31. Locking leg 730 caninclude a proximally or distally directed tab 738 that contactsintroducer needle 31 to minimize drag on introducer needle 31. Oncesharp distal tip 32 of introducer needle 31 is moved proximal of lockingleg 730, leaf spring 700 returns to its unbiased, i.e. activated,non-clipped position such that opening 735 is substantially aligned withthe longitudinal axis of introducer needle 31. In this position, springclip 799 no longer engages flange 44 of catheter hub 24 so that thecatheter can be disconnected from needle shield 40. See FIG. 77. Ifintroducer needle 31 is thereafter moved distally with respect to needleshield 40, sharp distal tip 32 of introducer needle 31 extends throughopening 735 until enlarged diameter portion 38 engages opening 735.Unwanted distal movement of introducer needle 31 is thus prevented sothat sharp distal tip 32 cannot be re-exposed outside needle shield 40.

Locking leg 730 can have a funnel configuration 736 adjacent to opening735. This funnel configuration 736 acts as a guide for introducer needle31 to ensure that it passes through opening 735 if introducer needle 31is moved distally after it has been withdrawn into needle shield 40.Funnel configuration 736 can be configured so that it is complementaryto the shape of the tapered distal portion 38 b of enlarged diameterportion 38 shown in FIG. 3C. Alternatively, locking leg 730 can bereplaced with a transverse barrier arrangement, such as shown in FIGS.74 and 75.

In order to place catheter 21 into a patient's blood vessel, theclinician substantially longitudinally aligns introducer needle 31 andcatheter 21 with the target blood vessel. The bevel of sharp distal tip32 should be facing substantially away from the skin surface duringvenipuncture. The clinician inserts introducer needle 31 and catheter 21at a shallow angle, preferably less than about 35 degrees, into the skinso that sharp distal tip 32 enters the target blood vessel. Theclinician then preferably observes a blood flashback in the flashbackchamber of needle hub 34.

After confirming placement of introducer needle 31 and catheter 21 inthe target blood vessel, the clinician advances catheter 21 distallyaxially along introducer needle 31 into position in the blood vessel. Incertain techniques, introducer needle 31 may be partially withdrawn intocatheter 21 before catheter 21 is completely advanced into position inthe blood vessel. After proper placement of catheter 21 is achieved, theclinician places a finger from her other hand on the patient's skin overthe blood vessel approximately over the distal end of catheter 21. Byplacing her finger on the patient's skin and applying sufficientpressure on the skin, the clinican thereby substantially occludes or atleast minimizes blood flow through catheter 21. The clinican thenwithdraws introducer needle 31 completely from catheter 21 by movingneedle hub 34 proximally. This movement causes introducer needle 31 tomove proximally into needle shield 40.

Where one of the embodiments of the spring clip disclosed herein toconnect needle shield 40 to catheter hub 24 until sharp distal tip 32 ofintroducer needle 31 has been withdrawn into needle shield 40 is used,needle shield 40 remains engaged with catheter hub 24 during thisproximal movement of introducer needle 31. Once sharp distal tip 32 ofintroducer needle 31 has been withdrawn into needle shield 40 so thatthe lock engages introducer needle 31 to prevent unwanted distalmovement of sharp distal tip 32 of introducer needle 31 out of thedistal end of needle shield 40, needle shield 40 can be disconnectedfrom catheter hub 24. After introducer needle 31 and needle shield 40have been removed from catheter hub 24, the clinician may then attach afluid delivery device, a PRN, a deadender cap or some other bloodmonitoring device to catheter hub 24 and commence the planned treatment.Introducer needle 31 and needle shield 40 may then be disposed ofaccording to the facility's disposal protocol.

Thus, it is seen that a catheter and introducer needle assembly withneedle shield is provided that is compact, simple and easy to use, thatrequires no special features or technique to be operative, thatautomatically shields the sharp distal tip of the introducer needle uponwithdrawal of the introducer needle from the catheter and where theneedle shield remains connected to the catheter until the needle shieldcovers the sharp distal tip of the introducer needle.

We claim:
 1. A catheter and introducer needle assembly, comprising: acatheter having a proximal end and a distal end; a catheter hub in fluidcommunication with the catheter and having a proximal end and a distalend connected to the proximal end of the catheter; an introducer needledisposed in the catheter and having a proximal end and a distal end, andan axis extending from the proximal end to the distal end; and a needleshield having a proximal portion and a distal portion and including aresilient clip that is adapted to flex between a biased position and anunbiased position in a plane substantially perpendicular to the axis onthe introducer needle; wherein, in the biased position, the clip engagesthe catheter hub and, in the unbiased condition, the clip disengages thecatheter hub; and wherein, when the distal end of the introducer needleextends from the distal portion of the needle shield, the clip is heldto one side of the introducer needle so it is flexed into the biasedposition and, when the sharp distal end of the introducer needle iswithdrawn into the needle shield, the clip flexes to the unbiasedposition out of engagement with the catheter hub.
 2. The catheter andintroducer needle assembly of claim 1 wherein the clip includes a springarm and at least one clip arm that extends from the spring arm.
 3. Thecatheter and introducer needle assembly of claim 2 wherein the clip armincludes a finger thereon.
 4. The catheter and introducer needleassembly of claim 3 wherein the finger mechanically engages the catheterhub to hold the catheter hub to the needle shield when the introducerneedle contacts the clip.
 5. The catheter and introducer needle assemblyof claim 4 wherein the finger has a proximal face and a distal face andwherein at least a portion of the finger proximal face engages thecatheter hub and at least a portion of the finger distal face engagesthe shield when the clip is in the biased condition.
 6. The catheter andintroducer needle assembly of claim 5 wherein, when the clip is In thebiased position, the shield engages the distal face of the finger toresist axial movement of the finger.
 7. The catheter and introducerneedle assembly of claim 5 wherein the catheter hub includes anengagement member which is mechanically engaged by the finger when theintroducer needle contacts the clip so the catheter hub is connected tothe needle shield until the distal end of the introducer needle iswithdrawn into the needle shield.
 8. The catheter and introducer needleassembly of claim 7 wherein the engagement member is a thread or detent.9. A catheter and introducer needle assembly, comprising: a catheterhaving a proximal end and a distal end; a catheter hub in fluidcommunication with the catheter and having a proximal end and a distalend connected to the proximal end of the catheter; an introducer needledisposed in the catheter and having a proximal end and a distal end; anda needle shield having a proximal portion and a distal portion andincluding a resilient clip having a generally V-shaped configurationincluding a pair of legs, which clip is adapted to flex into and out ofengagement with the catheter hub; wherein when the distal end of theintroducer needle extends from the distal portion of the needle shield,the introducer needle contacts the clip so that the pair of legs isretained to one side of the introducer needle and flexed into a biasedposition into engagement with the catheter hub and, when the sharpdistal end of the introducer needle is withdrawn into the needle shield,the introducer needle no longer contacts the clip so it can flex to itsunbiased position out of engagement with the catheter hub.
 10. Thecatheter and introducer needle assembly of claim 9 wherein the pair oflegs straddles the longitudinal axis of the assembly when the clip is inits unbiased position.
 11. The catheter and introducer needle assemblyof claim 10 wherein the V-shaped clip includes a clip arm extendinggenerally parallel to the longitudinal axis of the assembly.
 12. Thecatheter and introducer needle assembly of claim 11 wherein the clip armengages the catheter hub.
 13. The catheter and introducer needleassembly of claim 12 wherein the needle shield includes a ramp incliningtransversely to a longitudinal axis of the assembly and wherein the cliparm engages the ramp as the clip flexes to an unbiased position, whichguides the movement of the clip arm out of engagement with the catheterhub.
 14. A catheter and introducer needle assembly, comprising: acatheter having a proximal end and a distal end; a catheter hub in fluidcommunication with the catheter and having a proximal end and a distalend, wherein the distal end of the catheter hub is connected to theproximal end of the catheter; an introducer needle disposed in thecatheter and having a proximal end, a distal end and an axis; and aneedle shield having a proximal portion and a distal portion andincluding a means for engaging the catheter hub when the distal end ofthe introducer needle extends from the distal portion of the needleshield and for becoming disengaged from the catheter hub when the sharpdistal end of the introducer needle is withdrawn into the needle shield.15. The catheter and introducer needle assembly of claim 14 wherein themeans for engaging the catheter is adapted to move solely through aplane perpendicular to the axis of the introducer needle.
 16. Thecatheter and introducer needle assembly of claim 14 wherein the meansfor engaging the catheter hub comprises a resilient clip having agenerally V-shaped configuration.
 17. The catheter and introducer needleassembly of claim 16 wherein the resilient clip includes a clip arm. 18.The catheter and introducer needle assembly of claim 17 wherein the cliparm includes a finger thereon.
 19. The catheter and introducer needleassembly of claim 18 wherein the finger mechanically engages thecatheter hub to hold the catheter hub to the needle shield when theintroducer needle contacts the clip.
 20. A catheter and introducerneedle assembly, comprising: a catheter having a proximal end and adistal end; a catheter hub in fluid communication with the catheter andhaving a proximal end and a distal end connected to the proximal end ofthe catheter and having a thread or detent at the proximal end, anintroducer needle disposed in the catheter and having a proximal end anda sharp distal end; and a needle shield having a proximal portion and adistal portion and including a resilient clip having a generallyV-shaped configuration and having a spring arm and a clip arm having afinger thereon wherein clip arm and the finger are adapted to flex intoand out of engagement with the thread or detent of the catheter hub andhaving a ramp generally inclining transverse to the axis of theintroducer needle, wherein when the distal end of the introducer needleextends from the distal portion of the needle shield, the introducerneedle retains the clip in a biased position to one side of theintroducer needle so that the clip arm and finger are flexed into abiased position into engagement with the catheter hub and when thedistal end of the introducer needle is withdrawn into the needle shield,the introducer needle no longer retains the clip and the clip flexesperpendicularly to the needle axis to its unbiased position wherein theclip arm engages the ramp as the clip moves to its unbiased positioncausing the clip arm and finger to move out of engagement with thecatheter hub.